LCD Glass Research Articles

34.2: Optical Components Directly Molded on the LCD Glass Substrate

AbstractIn this paper, we describe the new process which we developed to mold precision optical components directly on a glass substrate of LCD using precision mastering by diamond cutting technique and photopolymer (2P) molding technique. We succeeded to mold a lens array on an LCD glass substrate with precise alignment to sub pixels of TFT array within six micrometer throughout the 13‐inch diagonal display area.

P‐28: Dry‐Etching Durability of LCD Glass Substrate Against Chlorine‐Based Gas

AbstractDry etching durability of Corning EAGLE2000 and code 1737 glass substrates was compared under aluminum gate metal over‐etching conditions of chlorine based reactive ion etching. The durability upon EAGLE2000 and code 1737 was equivalent against simulated aluminum dry etching condition. The etching rates of EAGLE2000 and code 1737 were less than 1/10 of sputtered aluminum film etching rate.

13.3: Suppression of Haze Formation on LCD Glass and Durability of the Substrate Etched by BHF

AbstractBuffered hydrofluoric acid etching during TFT manufacturing process sometimes causes haze on LCD glass substrates. In previous work, there was a recommendation of preliminary cleaning of substrate before BHF etching to solve haze problem. However, there was no suggestion for haze control during BHF etching process. In this paper, suppression of haze formation by agitation and dilution is discussed. Strong agitation and suitable amount of dilution are effective for haze suppression. A change of durability (corrosion rate) was observed depending on conditions of these methods.

13.1: Effect of Scribing Wheel Dimensions on the Cutting of LCD Glass Substrate

AbstractThe influence of the scribe wheel angle and diameter to the scribing and the breaking of LCD glass substrate, Code1737F, were experimentally investigated. A wheel having 130° tip angle and 4mm in diameter have shown the best results, allowing sheet separation at the lowest breaking force.

Composite robot end effector for manipulating large LCD glass panels

Recently, the design and the manufacture of light robot end effectors with high stiffness have become important in order to reduce the deflection due to the self-weight and weight of glass panel, a part of LCD, as the size of glass panels as well as robot end effectors increases. The best way to reduce the deflection and vibration of end effectors without sacrificing the stiffness of end effectors is to employ fiber reinforced composite materials for main structural materials because composite materials have high specific stiffness and high damping. In this work, the end effector for loading and unloading large glass panels were designed and manufactured using carbon fiber epoxy composite honeycomb sandwich structures. Finite element analysis was used along with an optimization routine to design the composite end effector. A box type sandwich structure was employed to reduce the shear effect arising from the low modulus of honeycomb structure. The carbon fiber epoxy prepreg was hand-laid up on the honeycomb structure and cured in an autoclave. A special process was used to reinforce the two sidewalls of the box type sandwich structure. The weight reduction of the composite end effector was more than 50% compared to the weight of a comparable aluminum end effector. From the experiments, it was also found that the static and dynamic characteristics of the composite end effector were much improved compared to those of the aluminum end effector.

Comprehensive Intraplant and Interplant Correlation of Photometric Measurements for Avionics LCDs

Honeywell has developed and implemented a comprehensive intraplant and interplant colorimeter certification method with traceability to NIST standards for inspection of avionics LCDs. To perform effective interplant correlation of optical measurements, special-purpose hardware was specified, designed, and built. Since the implementation of these procedures, increases in interplant correlation have helped to dramatically reduce the cycle time for LCD glass; and intraplant correlation has improved to the level where grouping in CIELuv space by colorimeters is no longer apparent.

Alumina barrier layers on LCD glass

Abstract Effective diffusion coefficients, D e , for the movement of sodium from an LCD glass into a sputtered alumina barrier layer have been determined. Secondary ion mass spectrometry analysis was used to measure sodium concentrations in 100 nm thick alumina films on soda lime glass at 520°C and for similar films on alkaline earth boroaluminosilicate glass at 650°C. Calculated values of D e are compared with extrapolated values of the diffusion coefficient, D , for sodium in polycrystalline alumina. The agreement is inconsistent. This is explained in terms of the countercurrent of hydrogen ions needed to maintain charge neutrality when a sodium ion moves out of the glass into the alumina film.

A plastic LCD design with high reliability and color-free readability

A new design has been developed for a plastic substrate twisted nematic LCD. The design results in color-free optical performance and high reliability as measured by accelerated life tests at high temperature and humidity. The crystalline nature of most chemically stable plastics has a biaxial birefringence which can produce dramatic interface colors in the twisted nematic geometry. Optically isotropic plastics are generally amorphous and, therefore, chemically incompatible with the liquid crystal which is a good organic solvent. This dichotomy has been solved by using a special form of polyester whose optic axes are controlled to lie at an angle from the normal which is considerably larger than the largest angle which can be reached by light entering the high index plastic. A fabrication process was developed to be consistent with the 150°C glass transition temperature for the polyester as opposed to the 500°C transition temperature of typical LCD glass substrates. Display materials were designed to be water tolerant, since all plastics transmit water. It was established on a laboratory scale that a plastic LCD design will pass consumer type reliability criteria for high-temperature and humidity stresses. Displays as large as 50 in2were fabricated and preliminary operational tests were encouraging. The plastic LCD process has been shown to be a technologically feasible manufacturing method and may hold promise for significant cost reduction over glass technology.