• Title/Summary/Keyword: LCD Glass

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Processing and Electrical Properties of COG(Chip on Glass) Bonding Using Fine-pitch Sn-In Solder Bumps (미세피치 Sn-In 솔더범프를 이용한 COG(Chip on Glass) 본딩공정 및 전기적 특성)

  • Choe Jae Hun;Jeon Seong U;Jeong Bu Yang;O Tae Seong;Kim Yeong Ho
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.11a
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    • pp.103-105
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    • 2003
  • COG (Chip on Glass) technology using solder bump reflow has been investigated to attach IC chip directly on glass substrate of LCD panel. As It chip and LCD panel have to be heated to reflow temperature of the so]der bumps for COG bonding, it is necessary to use low-temperature solders to prevent the damage of liquid crystals of LCD panel. In this study, using the Sn-52In solder bumps of $40{\mu}m$ pitch size, solder joints between Si chip and glass substrate were made at temperature below $150^{\circ}C$. The contact resistance of the solder joint was $8.58m\Omega$, which was much lower than that of the joint made using the conventional ACF bonding technique. The Sn-52In solder joints with underfill showed excellent reliability at a hot humid environment.

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Predictive models of hardened mechanical properties of waste LCD glass concrete

  • Wang, Chien-Chih;Wang, Her-Yung;Huang, Chi
    • Computers and Concrete
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    • v.14 no.5
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    • pp.577-597
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    • 2014
  • This paper aims to develop a prediction model for the hardened properties of waste LCD glass that is used in concrete by analyzing a series of laboratory test results, which were obtained in our previous study. We also summarized the testing results of the hardened properties of a variety of waste LCD glass concretes and discussed the effect of factors such as the water-binder ratio (w/b), waste glass content (G) and age (t) on the concrete compressive strength, flexural strength and ultrasonic pulse velocity. This study also applied a hyperbolic function, an exponential function and a power function in a non-linear regression analysis of multiple variables and established the prediction model that could consider the effect of the water-binder ratio (w/b), waste glass content (G) and age (t) on the concrete compressive strength, flexural strength and ultrasonic pulse velocity. Compared with the testing results, the statistical analysis shows that the coefficient of determination $R^2$ and the mean absolute percentage error (MAPE) were 0.93-0.96 and 5.4-8.4% for the compressive strength, 0.83-0.89 and 8.9-12.2% for the flexural strength and 0.87-0.89 and 1.8-2.2% for the ultrasonic pulse velocity, respectively. The proposed models are highly accurate in predicting the compressive strength, flexural strength and ultrasonic pulse velocity of waste LCD glass concrete. However, with other ranges of mixture parameters, the predicted models must be further studied.

Blackening of Inner Glass Surface in Fluorescent Lamps for LCD Backlight (LCD 백라이트용 형광램프의 흑화 현상)

  • Hwang, Ha-Chung;Jeong, Jong-Mun;Kim, Jung-Hyun;Kim, Dong-Jun;Bong, Jae-Hwan;Chung, Jae-Yoon;Koo, Je-Huan;Cho, Guang-Sup
    • Journal of the Korean Vacuum Society
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    • v.17 no.6
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    • pp.481-486
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    • 2008
  • The different degrees of blackening were observed at the inner surface of borosilicate, soda-lime, and aluminosilicate glass tubes having different sodium (Na) contents. The sodium contents ($Na_2O$) within the borosilicate, soda-lime, and aluminosilicate glass tubes were found to be 4%, 14%, and 0.06%, respectively. The degree of blackening was shown to increase as the sodium content within the glass of the fluorescent lamp containing Ne+Ar+Hg gas mixture. Higher degree of blackening was observed from the inner surface of the glass tube coated with $Y_2O_3$. The blackening was found to be originated from the amalgam of $NaHg_2$ generated by the chemical reaction between the mercury ions within the discharge gas and sodium within the glass tube during operation.

Assessment of compressive strength of cement mortar with glass powder from the early strength

  • Wang, Chien-Chih;Ho, Chun-Ling;Wang, Her-Yung;Tang, Chi
    • Computers and Concrete
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    • v.24 no.2
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    • pp.151-158
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    • 2019
  • The sustainable development principle of replacing natural resources with renewable material is an important research topic. In this study, waste LCD (liquid crystal display) glass powder was used to replace cement (0%, 10%, 20% and 30%) through a volumetric method using three water-binder ratios (0.47, 0.59, and 0.71) to make cement mortar. The compressive strength was tested at the ages of 7, 28, 56 and 91 days. The test results show that the compressive strength increases with age but decreases as the water-binder ratio increases. The compressive strength slightly decreases with an increase in the replacement of LCD glass powder at a curing age of 7 days. However, at a curing age of 91 days, the compressive strength is slightly greater than that for the control group (glass powder is 0%). When the water-binder ratios are 0.47, 0.59 and 0.71, the compressive strength of the various replacements increases by 1.38-1.61 times, 1.56-1.80 times and 1.45-2.20 times, respectively, during the aging process from day 7 to day 91. Furthermore, a prediction model of the compressive strength of a cement mortar with waste LCD glass powder was deduced in this study. According to the comparison between the prediction analysis values and test results, the MAPE (mean absolute percentage error) values of the compressive strength are between 2.79% and 5.29%, and less than 10%. Thus, the analytical model established in this study has a good forecasting accuracy. Therefore, the proposed model can be used as a reliable tool for assessing the design strength of cement mortar from early age test results.

The Influence of Charged Static Electricity on LCD Glass and Neutralization Characteristic by Soft X-ray

  • Choi, Chang-Hoon;Han, Sang-Ho;Park, Sun-Woo;Yun, Hae-Sang
    • Journal of Information Display
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    • v.1 no.1
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    • pp.52-58
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    • 2000
  • We observed that static electricity has an influence on the etching unformity of dry etching process. When the static electricity was applied from-200[V]to-1000[V] on glass substrates, the etching rate uniformity was changed to 1.5%-15%. In this experiment, the soft X-ray to neutralize static electricity was adopted as ore of neutralization methods. As an experimental result, soft X-ray irradiation improved neutralization capability on the surface of LCD glass substrate within the short time, about 15-30sec. The difference of etching rate uniformity was below 0.5%.

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Precise Measurement of Optical Anisotropy of Rubbed Polyimide on Patterned Glass and its Nanoscale Variation (패턴이 있는 유리기층 위 러빙된 Polyimide의 광학 이방성 미세변화 정밀 측정)

  • Kim, Ha-Rang;Kim, Sang-Youl
    • Korean Journal of Optics and Photonics
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    • v.20 no.5
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    • pp.281-287
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    • 2009
  • The optical anisotropy of rubbed PI(polyimide) film on patterned LCD glass substrate is analyzed using polarimetry. The direction of the optic axis and the magnitude of the very small retardation ($\sim$ 0.4 nm or less) is precisely measured by using a transmission ellipsometer. The variation of the optical anisotropy is presented as the curve of the optic axis versus the magnitude of the phase retardation and it is explained by using a simple optical model.

Electro-Optical characteristics on the rubbing-aligned plastic Twisted Nematic cell (플라스틱 러빙처리된 TN셀의 전기광학 특성)

  • Nam, Ki-Hyung;Hwang, Jeoung-Yeon;Kim, Jong-Hwan;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.04a
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    • pp.18-22
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    • 2004
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on polyimide surfaces using thin plastic substrates. It was found that monodomain alignment of NLC is obtained with rubbing alignment method on polyimide surfaces using thin plastic substrates. The NLC pretilt angles generated are about $3^{\circ}$ by the rubbing alignment method on thin plastic substrates, However, the pretilt angle are at about $1.7^{\circ}$ lower on the glass substrate than on thin plastic substrate. Also, EO characteristics of the TN-LCD with a rubbed PI surface based on polymer are almost the same as that of the TN-LCD with a rubbed PI surface based on glass. However, the transmittances of the TN-LCD with a rubbed PI surface based on polymer is less than that with a rubbed PI surface based on glass.

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Numerical Study on the Air-Cushion Unit for Transportation of Large-Sized Glass Plate

  • Jun, Hyun-Joo;Kim, Kwang-Sun;Im, Ik-Tae
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.1 s.18
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    • pp.59-64
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    • 2007
  • Non-contact transportation of a large-sized glass plate using air cushion for the vertical sputtering system of liquid crystal display (LCD) panel was considered. The objective of the study was to design an air pad unit which was composed of multiple injection and exhaust holes and mass flow supplying pipe. The gas was injected through multiple small holes to maintain the force for levitating glass plate. After hitting the plate, the air was vented through exhaust holes. Complex flow field and resulting pressure distribution on the glass surface were numerically studied to design the air injection pad. The exhaust hole size was varied to obtain evenly distributed pressure distribution at fixed diameter of the injection hole. Considering the force for levitating glass plate, the diameter of the exhaust hole of 30 to 40 times of the gas injection hole was recommended.

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