| 摘要 |
PURPOSE:To enable punching with high accuracy without damage such as chipping of glass by forming a preliminarily processed hole on the substrate on the side opposite to the surface to be started with punching then processing a through-hole in the substrates. CONSTITUTION:A preliminarily processed hole 13 is formed beforehand by a drill 8 of a sintered hard alloy or the like in a part of a glass substrate 2b on the side opposite to the surface to be started with punching. A through-hole 3 is formed in the glass substrates 2a, 2b by the drill 8 from the surface to be started with punching of the glass substrate 2a after the above-mentioned formation. |
