Tempered glass manufacturing is a processing technology that imparts high strength and safety to ordinary glass. The main manufacturing methods include "thermal tempering (physical tempering)," which involves heating the glass close to its softening point and rapidly cooling it to create a compressive stress layer on its surface, and "chemical tempering," which forms a compressive stress layer by replacing alkali ions on the glass surface with larger ions. As a result, impact resistance and thermal shock resistance are significantly improved. Furthermore, even if it breaks, the fragments shatter into small pieces, reducing the danger from scattering. It is used as an indispensable material in a wide range of fields where high safety and durability are required, such as windows and doors of buildings, side and rear windows of automobiles, smartphone displays, and protective covers for home appliances.