GLASS SUBSTRATE, FLAT-PANEL DISPLAY DEVICE USING THE SAME GLASS SUBSTRATE AND HEAT TREATMENT OF THE SAME GLASS SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a glass substrate which is used for a low temp. p-Si TFT (thin film transistor) liquid crystal display device and has a small thermal shrink age factor in performing secondary thermal treatment in the manufacture of the liquid crystal display device. SOLUTION: This glass substrate comprises glass having a >=600 deg.C strain point. This heat treatment is performed under conditions such that the temp. of the substrate is raised from ordinary temp. to a temp. of ((the strain point of glass)-(40 to 150 deg.C)) at a 100 deg.C/min rate and then maintained at that temp. by heating the substrate and thereafter, lowered to ordinary temp. at a 100 deg.C/min rate, wherein the difference between dimensions of the glass substrate before and after the heat treatment is <=±20 ppm at the time of maintaining the substrate at the above specified temp. for any period of time of 30 min and 5 hr by heating it.