| 摘要 |
PURPOSE:To cut out a doughnut-shaped substrate from a fragile material such as flat glass by the operation from the single surface of said material using a single work without moving a work place to grind the same. CONSTITUTION:The core drill 13 and skirt drill 14 of a work 1 being a cutting and grinding tool are brought into contact with a hard and fragile material such as a glass plate and urged into the fragile material to cut out a doughnut- shaped substrate 21 and, in this state, the doughnut-shaped substrate 21 and the work 1 are relatively moved so as to introduce the doughnut-shaped substrate 21 into the work 1 to bring the inner peripheral part and peripheral edge part of the doughnut-shaped substrate 21 into contact with the annular recessed parts 8 respectively formed to a core rod 4 and a skirt 5. Since the inner peripheral part and peripheral edge part of the doughnut-shaped substrate 21 are ground, the cutting-out and grinding of the doughnut-shaped substrate can be performed by consistent work from the single surface of the fragile material. |
