| 摘要 |
PURPOSE:To accelerate an inspection speed by dispensing with preparation for blocking a through-hole from light, by arranging a rotor cooperated with a print board in a closely contacted state to the illumination side of said printed circuit board while blocking the through-hole from light by the mutual movement of the rotor and the print board. CONSTITUTION:A plating layer 3 is formed to the inner wall of a light pervious hole 2a provided by drilling to the light pervious substrate material 2 of a print board 1 to form a through-hole 4. Light 5 from a defect inspecting light source is allowed to irradiate one surface side of the print board 1 and a roll shaped rotor 6 for blocking the through-hole 4 from light is arranged to the illumination side. The rotor 6 has a length for simultaneously blocking the through-hole 4 from light and supported in a revolvable manner by an arm 8 while a torsion spring 9 is provided to the arm 8 under tension to bring said rotor 6 into close contact with the light irradiated surface of the print board 1. A light detector 10 is arranged to the other surface side of the print board 1 so as to be opposed to the rotor 6 and, when there is a defect 3a in the through- hole 4, light incident to the substrate material 2 from the periphery of the rotor 6 is diffused in the substrate 2 to generate bright light in the through-hole to enable defect detection. By this method, an inspection speed is accelerated. |
