59.4: A Novel Route for Thinning of LCD Glass Substrates

Abstract

The present work describes methods to reduce the thickness of glass substrate used in a liquid crystal display (LCD). Reduction of the thickness improves a thin and ligh-weight performance of LCDs. For this purpose, a fluoride-base chemical was introduced as an etchant of the LCD glass. The new etchant was tested and evaluated by comparing it with the conventional etchant, hydrofluoric acid. An apparatus was also introduced. In the apparatus, rollers were used to remove the reaction products of the etchant and glass. Operation of a pilot-scale equipment showed that the total thickness variation and surface roughness, Ra, was less than 1.0 μm and 0.01 μm, respectively, when the LCD glass plate of 550×650mm was thinned from 0.8 mm to 0.61 mm. This indicates that the thinning process developed in the present work can be directly applied to make small-sized LCD modules such as PDAs, cellular phones, digital cameras, etc., using the 0.6 mm thick glass without any additional process like polishing. Improvement of yield is expected due to remarkable improvement of thickness uniformity. Modification of the present process is needed for making large-sized LCD modules for notebook computers using the 0.4 mm or thinner glass.