| 摘要 |
PURPOSE:To efficiently bore the flawless inlet and outlet tiny holes having almost uniform and stabilized diameters with high roundness and precision by boring the holes through a ceramic green sheet with many punches, then embedding the punches in the sheet, calcining the sheet and then melting off the punch. CONSTITUTION:Many inlet holes 13 and outlet holes 14 in succession to the inlet hole are bored through an uncalcined ceramic green sheet 1 using many punches 12 each having a tapered part 10 inclined at about 30 deg. to vertical and an extremely small-diameter part 11 in succession to the tapered part 10 with its tip rounded. The punch 12 is embedded in the holes 13 and 14. The green sheet 1 is then calcined at about 1700 deg.C, and the punch 12 is dissolved off by aqua regia to form a tiny hole 15. When a punch made of a material having a m.p. lower than the calcination temp. is used, the punch is melted off when the green sheet is calcined, hence the punch need not be removed, and the procedure is made more efficient. |
