METHOD OF BORING GLASS SUBSTRATE AND GLASS SUBSTRATE FOR PLASMA DISPLAY MANUFACTURED BY THE METHOD

摘要

A first hole of a predetermined depth is formed in a glass substrate by pressing a first drill against the lower surface of the glass substrate while rotating the first drill. A second hole is formed in the glass substrate by pressing a second drill against the upper surface of the glass substrate at the position facing the first hole while rotating the second drill. A through-hole is formed in the glass substrate by connecting the first hole with the second hole. Since the first and second holes are overlapped with each other in the thickness direction of the glass substrate, a step part formed on the inner peripheral part of the through hole is positioned on the upper surface side higher than the center of the glass substrate in the thickness direction.