| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of through holes at the end face of a board by preventing production of cutting residue of a metallic plating layer at the inside of the through holes of the end face so as to avoid the production efficiency from being deteriorated. SOLUTION: The printed circuit board 11 is cut by pressing a blade edge of a metallic die (not shown) along a cutting line A deviated from the center 12a of each through-hole 12 toward the center of the printed circuit board 11 by 0.1 to 0.2 mm to form each end face through-hole 15 to the end face of the printed circuit board 11. Since the blade edge of the metallic die crosses an inner circumferential face of each through-hole 12 at an obtuse angleαin this cutting, and the cutting stress in this case acts on each through-hole 12 in an outward direction resulting in that the metallic plating layer 13 sneaks away to the outside of each through-hole 12; no cutting residue of the metallic plating layer 13 is caused to the inside of each end face through-hole 15. COPYRIGHT: (C)2005,JPO&NCIPI
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