• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1272-1275
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• 2008

We present the development of dry etch process for the liquid crystal display (LCD) fabrication using a dielectric barrier discharge (DBD) system at atmospheric pressure. In this experimental work, the dry etch characteristics and the electrical properties of thin film transistor are evaluated by using the scanning electron microscopy and electric probe, and TFT-LCD panel ($300\;mm\;{\times}\;400\;mm$) is manufactured with the application of the amorphous silicon etch step in the 4 mask and 5 mask processes.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.105-124
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• 2011

TFT-LCD consists of LCD panel on the top, circuit unit on the side and BLU on the bottom. The recent development issues of BLU-dependent TFT-LCD have been power consumption minimization, slimmerization and size maximization. As a result of this trend, LED is adopted as BLU instead of CCFL to increase brightness and to reduce thickness. In liquid crystal displays, the light efficiency is below 10% due to the loss of light in the path from a light source to an LCD panel and presence of absorptive polarizer. This low efficiency results in low brightness and high power consumption. One way to circumvent this situation is to use a reflective polarizer between backlight units and LCD panels. Since a nano-wire grid polarizer has been known as a reflective polarizer, an idea was proposed that it can be used for the enhancement of the brightness of LCD. The use of reflective polarizing film is increasing as edge type LED TV and 3D TV markets are growing. This study has been carried out to fabrication of the nano-wire grid polarizer(NWGP) and investigated the brightness enhancement of LCD through polarization recycling by placing a NWGP between an c and a backlight unit. NWGPs with a pitch of 200nm were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the UV imprinting and was applied to plastic PET film. In this case, the brightness of an LCD with NWGPs was 1.21 times higher than that without NWGPs due to polarization recycling.

• Journal of Information Display
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• v.6 no.3
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• pp.18-21
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• 2005

A new technology for reducing photolithography process from a four step to a three step process in the fabrication of TFT LCD is introduced. The core technology for 3-mask-TFT processes is the lift-off process [1], by which the PAS and PXL layers can be formed simultaneously. A different method of the lift-off process was developed in order to enhance the performance of efficiency with conventional positive and not negative PR which is the generally used in other lift-off process. In addition, the removal capacity of the ITO/PR in lift-off process was evaluated. The evaluation results showed that the new process can be run in conventional TFT production condition. In order to apply this new process in existing TFT process, several tests were conducted to ensure stability of the TFT process. It was found that the outgases from PR on the substrate in ITO sputtering chamber do not raise any problem, and the deposited ITO film beside the PR has conventional ITO qualities. Furthemore, the particles that were produced due to the ITO chips in PR strip bath could be reduced by the existing filtering system of stripper. With the development of total process and design of the structure for TFT using this technology, 3-mask-panels were achieved in TN and IPS modes, which showed the same display performances as those with the conventional 4mask process. The applicability and usefulness of the 3-mask process has already verified in the mass production line and in fact it currently being used for the production of some products.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.376-379
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• 2007

Although years of trials for the fabrication of TFT LCD color filters with the piezo Drop-On-Demand (DOD) inkjet printing technology have been made, the underlying physics of jetting and wetting has not been fully understood. In this study, the key engineering issues, jetting and wetting, are investigated with mathematical models.

• Journal of Information Display
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• v.10 no.1
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• pp.33-36
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• 2009

A new hybrid silicon thin-film transistor (TFT) fabrication process using the DPSS laser crystallization technique was developed in this study to realize low-temperature poly-Si (LTPS) and a-Si:H TFTs on the same substrate as a backplane of the active-matrix liquid crystal flat-panel display (AMLCD). LTPS TFTs were integrated into the peripheral area of the activematrix LCD panel for the gate driver circuit, and a-Si:H TFTs were used as a switching device of the pixel electrode in the active area. The technology was developed based on the current a-Si:H TFT fabrication process in the bottom-gate, back-channel etch-type configuration. The ion-doping and activation processes, which are required in the conventional LTPS technology, were thus not introduced, and the field effect mobility values of $4\sim5cm^2/V{\cdot}s$ and $0.5cm^2/V{\cdot}s$ for the LTPS and a-Si:H TFTs, respectively, were obtained. The application of this technology was demonstrated on the 14.1" WXGA+(1440$\times$900) AMLCD panel, and a smaller area, lower power consumption, higher reliability, and lower photosensitivity were realized in the gate driver circuit that was fabricated in this process compared with the a-Si:H TFT gate driver integration circuit

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2563-2566
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• 2007

TFT LCD industries have endeavored to adopt the piezo Drop-On-Demand (DOD) inkjet printing technology to production lines of TFT LCD color filters and these efforts have significantly been based on experimental works. Because the degree of complexity in the piezo DOD inkjet printing technology results in too many combination of parameters, the matrix experimental method to investigate all possible sets of parameters becomes ineffective and hence the basic understanding of the piezo Drop-On-Demand inkjet print technology becomes important. In this study, one possible cause of the droplet volume variation across nozzles, which might cause visible swathe marks on an inkjet patterned TFT LCD color filter, is theoretically investiaged and new R&D directions are suggested.

• Journal of Information Display
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• v.7 no.3
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• pp.1-4
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• 2006

2.22-inch qVGA $(240{\times}320)$ amorphous silicon thin film transistor liquid active matrix crystal display (a-Si TFT-AMLCD) panel has been successfully demonstrated employing a 2.5 um fine-patterning technology by a wet etch process. Higher resolution 2.22-inch qVGA LCD panel with an aperture ratio of 58% can be fabricated as the 2.5 um fine pattern formation technique is integrated with high thermal photo-resist (PR) development. In addition, a novel concept of unique a-Si TFT process architecture, which is advantageous in terms of reliability, was proposed in the fabrication of 2.22-inch qVGA LCD panel. Overall results show that the 2.5 um fine-patterning is a considerably significant technology to obtain higher aperture ratio for higher resolution a-Si TFT-LCD panel realization.

• IE interfaces
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• v.22 no.1
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• pp.1-9
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• 2009

As the LCD fabrication factories (Fab) are highly capital-intensive and the markets are very competitive, it is an essential requirement of operational management to achieve full-capacity production while meeting customer demands on time. In a typical LCD Fab, medium-term schedules such as release plans and production plans are critical to achieve the goal of full-capacity production and on-time delivery. Presented in this paper is a framework for weekly planning system generating medium-term schedules using a finite-capacity planning method. Also this paper presents a release planning method applying capacityfiltering algorithm, especially backward capacity-filtering procedure, which is one of the finite-capacity planning methods. In addition, performance analyses using actual data of a TFT-LCD Fab show that the proposed method is superior to existing methods or commercial S/W products generating release plans.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.205-207
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• 2008

The new process for hybrid silicon thin film transistor (TFT) using DPSS laser has been developed for realizing both low-temperature poly-Si (LTPS) TFT and a-Si:H TFT on the same substrate as a backplane of active matrix liquid crystal display. LTPS TFTs are integrated on the peripheral area of the panel for gate driver integrated circuit and a-Si:H TFTs are used as a switching device for pixel in the active area. The technology has been developed based on the current a-Si:H TFT fabrication process without introducing ion-doping and activation process and the field effect mobility of $4{\sim}5\;cm^2/V{\cdot}s$ and $0.5\;cm^2/V{\cdot}s$ for each TFT was obtained. The low power consumption, high reliability, and low photosensitivity are realized compared with amorphous silicon gate driver circuit and are demonstrated on the 14.1 inch WXGA+ ($1440{\times}900$) LCD Panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.15-20
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• 2005

We have achieved 180-degree angle of view performance using Super-PVA (S-PVA) technology first time in TFT-LCD industry. 82" full high definition ($1920{\times}1080$) TFT- LCD panel, the world's largest TFT-LCD, have been developed. In addition to the size breakthrough, this product achieves 600nits brightness, over 1200:1 contrast ratio, viewing angle free, 92% color gamut, and 8ms response time. Several key enabling technologies were developed to achieve these specifications, including two transistor direct driven independently controlled S-PVA subpixels, non even area ratio sub-pixels for optimal offaxis gamma, gate overlap driving for larger driving margin, new CCFL technology for higher color gamut, and advanced fabrication techniques including the use of Samsung's new $7^{th}$ generation line.