| 摘要 |
PURPOSE:To enable an improved via hole without any remainder of foreign objects such as chips to be formed by preparing a ceramic green sheet which was backed by resin film and by discharging the chips of ceramic green sheet from the tool nose part while pressing out a pin. CONSTITUTION:A ceramic green sheet (2g) backed by a resin film 10 such as polyethylene terephthalate is prepared. Also, a conical drilling tool 22 with a tool nose part 26 at the tip and a round pin 24 which can move up and down within the inside is prepared. The outside of this tool nose part 26 is in conical shape spreading upward and the diameter of the hole 28 nearly corresponds to the diameter of via hole to be opened. The tool nose part 26 is pushed into a specified position of the ceramic green sheet (2g) from the above. Then, if the drilling tool 22 is lifted, the chips 30 enter the tool nose part 26 of the drilling tool 22 and is lifted simultaneously with lifting of the drilling tool 22. Then, if the pin 24 within the drilling tool 22 is pushed into the tip at a proper position, the chips 30 are discharged from the tip part 26. |
