| 摘要 |
<p>Disclosed is a method to punch a plurality of holes of fine diameter d on brittle material at fine intervals alpha . The method includes the steps of forming at least two holes including a hole of fine diameter d at intervals A, each of which is at least two times the fine interval a, by the use of a punching die, and punching holes between the previously punched holes at intervals A so that the distance from the punched holes of diameter d measures at least the distance corresponding to the fine interval alpha , without removing the punches used to form the holes in the previous step. The die comprises a plurality of punches having punching tips, a punch plate for holding said punches, a die including a plurality of fine holes of prescribed diameter for inserting and removing the punching tips of said punches, and a stripper disposed between said punch plate and said die for holding the tips of said punches and peeling brittle material to be punched off said punch when removing said punches from said die. A plurality of punches is composed of at least two groups of punches in which the positions of the apexes of the respective tip portions differ from each other. <IMAGE></p> |
