Glasses for display panels and photovoltaic devices

Abstract

An aluminosilicate glass having a composition consisting essentially of, as calculated in weight percent on an oxide basis, of 58-70% SiO2, 12-22% Al2O3, 3-15% B2O3, 2-12% CaO, 0-3% SrO, 0-3% BaO, 0-8% MgO, 10-25% MCSB (i.e., MgO+CaO+SrO+BaO), and SrO and BaO in combination being less than 3%.

Description

[0001]This application claims the benefit of U.S. provisional application Ser. No. 60 / 033,603, filed Dec. 17, 1996.FIELD OF THE INVENTION[0002]The invention relates to a family of aluminosilicate glass compositions exhibiting physical and chemical properties suitable for flat panel display.BACKGROUND OF THE INVENTION[0003]Liquid crystal displays (LCDs) are passive flat panel displays which depend upon external sources of light for illumination. They are manufactured as segmented displays or in one of two basic configurations. The substrate needs (other than being transparent and capable of withstanding the chemical conditions to which it is exposed during display processing) of the two matrix types vary. The first type is intrinsic matrix addressed, relying upon the threshold properties of the liquid crystal material. The second is extrinsic matrix or active matrix (AM) addressed, in which an array of diodes, metal-insulator-metal (MIM) devices, or thin film transistors (TFTs) suppl...

AI Technical Summary

Benefits of technology

[0017]The glasses of the present invention exhibit a coefficient of thermal expansion (CTE) in the range of 30-39 (more preferably 31-38, and most preferably 32-38)×10−7 / ° C., from 25-300° C. and a high strain point (at least 650° C., preferably greater than 675° C., in order to eliminate or minimize the need for a pre-compaction annealing step. Low density (preferably less than 2.5 g / cm3, most preferably less than 2.4 g / cm3) and high Young's modulus is desirable to minimize display weight and panel sag and at the same time maximize hardness in order to improve resistance to scratching and edge defects.

Problems solved by technology

Third, that the expansion mismatch between the glass and the silicon present in the TFT array be maintained at a relatively low level even as processing temperatures for the substrates increase; and

Thus, the initial LCD devices did not have their driver chips mounted on the substrate glass.

As LCD device technology improved and as the devices became larger and required finer resolutions, these flexible mountings became unacceptable, both because of cost and of uncertain reliability.