| 摘要 |
PURPOSE: To drill holes from a surface layer to a desired internal layer even if a multi-layered printed circuit board warps by using the point where a drill abuts on an abutting plate as a starting point and feeding the drill a set feed amount from this starting point to drill. CONSTITUTION: An abutting plate 3 made of conductive materials is put on the top face of a multi-printed circuit board 1, and voltage is applied between a drill 2 and abutting plate 3 beforehand, and in drilling the multi-layered printed circuit board while driving the drill 2, the point where electrical conduction is detected between the drill 2 and the abutting plate 3 is used as a starting point 20. The drill 2 is fed from the starting point 20 the feeding amount set, forming a surface layer IVH in the multi-layered circuit board 1. At this moment, voltage is applied to the abutting plate 3 through a stack pin 5 positioning and fixing the multi-layered printed circuit board 1 and abutting plate 3. |
