| 摘要 |
<p>A blind hole pair is formed on a PCB by drilling the PCB. Blind holes in the blind hole pair have mouths respectively on an upper surface and a lower surface of the PCB and have a displacement. The sum of the depths of the blind holes in the blind hole pair is larger than the thickness of the PCB, and the displacement is smaller than the sum of the radii of the blind holes in the blind hole pair, so as to make the bottoms of the blind holes form an overlap area.</p> |
