| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance processing efficiency by a core drill and to make chippings generated on a rear surface side of a glass substrate small. <P>SOLUTION: The core drill 10 has a rotating shaft 12, a support plate 14, a cylindrical part 16 and a grinding part 18. A point 19 of the grinding part 18 is formed in the shape of a circular arc whose vertical cross-sectional shape is the same radius. Therefore, the contact width of an edge of a blade brought into first contact with the surface of a glass element substrate 20 is made small with respect to the surface of the glass element substrate 20, and the contact width of the edge of a blade of the core drill 10 brought into contact with the surface of the glass element substrate 20 is gradually changed to be wider in accordance with the fall of the core drill 10. An annular groove 42 into which the point 19 of the core drill 10 is formed on the top surface of a stage 40 on which the glass element substrate 20 is mounted. In the annular groove 42, groove width X1 in a radial direction is formed larger than the drill width X of the point 19 of the core drill 10 so as not to come into contact with the point 19 of the core drill 10 (X1>X). <P>COPYRIGHT: (C)2013,JPO&INPIT |
