Method for improving measurement of bending stress in ion-exchange chemically strengthened glass containing lithium

摘要

Methods are disclosed for improving the measurement of bending stress in an ion-exchanged chemically strengthened Li-containing glass sample comprising a flexure. One of the methods includes compensating for a shift in the position of the TIR-PR potential position associated with the critical angle position, which shift is due to the presence of a leak mode. Another method involves applying selection criteria to the captured modal spectral image to ensure that a high quality image is used to calculate bending stress. Other methods combine direct and indirect measurements of bending stress using mode spectra from multiple samples to obtain greater accuracy and precision compared to using the direct measurement method or the indirect measurement method alone. A quality control method for forming a glass sample using the measured mode spectrum and related techniques to ensure accurate measurement of bending stress is also disclosed.