Environmentally-friendly alkali-free aluminoborosilicate glass for TFT-LCD

Abstract

The invention relates to alkali-free aluminoborosilicate glass for manufacturing a flat-panel display. The glass comprises the following chemical components in percentage by weight: 55 to 70 percent of SiO2, 7 to 13 percent of B2O3, 14 to 21 percent of Al2O3, 5 to 11 percent of CaO, 0.5 to 10 percent of SrO, 0.1 to 0.2 percent of SnO2, and 0.1 to 4.0 percent of Y2O3, wherein the glass does not contain MgO or BaO. The density of the glass is less than 2.45g / cm<3>, and the glass has the advantages of low glass smelting temperature, strain point of more than 700 DEG C, low thermal expansion coefficient, large elastic modulus, high strength, no alkali metal oxide, liquidus temperature of lower than 1,150 DEG C and the like, and is suitable for manufacturing the flat-panel display, in particular the substrate glass for displaying of a thin film transistor-liquid crystal display (TFT-LCD).

Description

technical field [0001] The invention relates to an alkaline earth metal aluminoborosilicate glass with high strain point temperature, low thermal expansion coefficient, large elastic modulus and no alkali metal oxide, which is suitable for manufacturing flat panel display substrate glass, according to the alkali-free aluminum boron The composition and production of silicate glass, the invention also relates to the application of the glass substrate in thin film transistor liquid crystal display (TFT-LCD), in particular to the chemical composition of an alkali-free aluminoborosilicate glass. Background technique [0002] Since the 21st century, flat panel display technology and its products have developed rapidly in electronic display products (such as notebook computers, LCD desktop computers, and LCD TVs) due to their advantages of thinness and lightness. High-definition, large-screen, thin wall-mounted Color television sets have entered families, and have gradually replace...

AI Technical Summary

Problems solved by technology

The visual quality of the glass screen, that is, the lack of crystalline impurities, stones and air bubbles is very good, because defects such as tiny air bubbles, stones, stripes, surface pits, and surface scars will cause errors in the display and affect the quality of the displayed image

[0014] Chinese patent CN200410045636.4 (authorized announcement number: CN 1275889C) describes the glass used for flat panel displays. The composition described in the patent is produced by the overflow melting method, and all properties meet the requirements of flat panel displays. However, the above as Example Although it does not contain the heavy metal element BaO, which is harmful to the environment, the listed clarifying agent Sb 2 o 3 and As 2 o 3 Because it does not meet the requirements of modern environmental protection and future development direction, it is no longer suitable for TFT-LCD substrate glass production

[0015] Although the clarified chemical composition of the aluminoborosilicate glass described in Chinese patent CN 101208276A does not contain elements harmful to the environment, the examples listed in the patent contain MgO, a substance that easily causes glass devitrification, resulting in the liquidus of the glass temperature rise

[0017] The element BeO contained in the formula of the alkali-free glass described in Chinese patent CN 101186438A is unfavorable to raising the strain point of the glass, and the substance of the clarifying agent is not clearly pointed out, and the formula also contains ZrO which is unfavorable to the density of the glass 2

[0018] Although the aluminoborosilicate glass with high elastic modulus and its application described in Chinese patent CN 101117270A has also added the substance Y that can improve the elastic modulus 2 o 3 , but its formula composition also includes BaO, a heavy metal element that is harmful to the environment, and the thermal expansion coefficient of the glass is quite different from that of the thin film transistor material. During the heat treatment, the glass plate will warp

[0019] The formula composition of alkali-free aluminoborosilicate glass and its application described in Chinese patent CN 1525945A contains a large amount of MgO which is easy to cause devitrification of the glass, which makes the liquidus temperature of the glass rise, which is not conducive to the production of the substrate , and the thermal expansion coefficient of the listed glass composition is quite different from that of the amorphous silicon thin film material, and it contains BaO, a heavy metal element that is harmful to the environment.

[0020] The formula composition listed in the TFT substrate glass described in Chinese patent CN 101066836A contains V which is harmful to the environment 2 o 5 , and the heavy metal elements BaO and La 2 o 3 , Sb 2 o 3 Not good for the environment, and its density is too high

[0021] Chinese patent CN 1445186A describes Al 2 o 3 The content is too low, which is not conducive to improving the strain point of the glass, SiO 2 If the content is too low, it is not conducive to glass forming, and its density is too high, the thermal expansion coefficient is too high, and the thermal expansion coefficient difference between the amorphous silicon film material is large

[0031] Although the high strain point glass described in the Chinese patent CN 101243018A has a high strain point, the examples listed contain a large amount of rare earth element La 2 o 3 , while the rare earth element La 2 o 3 It is very likely that the fluorescence effect will occur in a certain wavelength range, especially the density of the glass will be increased, and the price is very expensive, so it is not suitable for the preparation of TFT-LCD substrate glass

[0032] The high strain point glass described in Chinese patent CN 1902138A contains P which is unfavorable to the glass strain point 2 o 5 At the same time, it leads to a decrease in the strength of the glass and a decrease in chemical resistance, and the thermal expansion coefficient of the listed formula composition is quite different from that of the amorphous silicon thin film material, so it is not suitable as a TFT-LCD substrate glass.

The strain point of these glasses is about 660°C, so they have excellent heat resistance, but these glasses have different thermal expansion coefficients and densities, and the 1737 glass substrate does not meet the requirements of the modern environmental protection market, while Eagle XG glass has obvious The higher liquidus temperature increases the energy consumption of glass production and preparation. The purpose of the present invention is to provide a glass substrate suitable for preparing displays without alkali metals, which not only meets the performance requirements of the modern market for environmental protection, but also meets the requirements of environmental protection in the modern market. Ensure that production energy consumption is reduced as much as possible without affecting various performances, and meet the requirements of energy conservation and environmental protection in the modern market

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