| 摘要 |
PROBLEM TO BE SOLVED: To improve yield of bored films by preventing residue of cutting chips even on the lowest film in superposing the films, and boring them from above. SOLUTION: Films or the like F are superposed in multiple layers, a rest is disposed under the superposed films F, and a drill 2 is rotated to be moved down toward them for boring holes in the superposed films F, where an underfilm 5 is placed between the lowest layer of the superposed films F and the rest 3, thereby residue of cutting chips of the films F is prevented.
|
