A new measurement method of thermal dimensional stability of glass and its application to LCD substrates

A novel and simple method to measure dimensional change of glass substrates for liquid crystal display (LCD) application, which ideally has a measurement capability of +/- 1.5 ppm, has been developed. Measurement accuracy was demonstrated for the reproducibility, test. By using this method, thermal shrinkage of Corning Code 7059, 1733 and 1737 glasses in the order of ppm was evaluated for various thermal cycles. Glass, having a higher strain point, has a higher thermal dimensional stability at a-Si TFT fabrication processes. Thermal shrinkage is smaller for lower pro cess temperatures and shorter process times. Annealing increases the thermal dimensional stability of the glass at a-Si TFT fabrication processes.