| 摘要 |
PURPOSE:To make a precise decision on whether chip parts are present or not by using a bottom plate which has light transmittable areas at positions of chip parts on a light transmittable printed circuit board and a light shielding area at the remaining part. CONSTITUTION:The light transmittable printed circuit board 4 is held at a specific position by a holding part 5. This holding part 5 consists of a frame body 6 and the light nontransmittable bottom plate 7 (made of, for example, metal), and the printed circuit board 4 is fitted and held in the recessed part formed by the frame body 6 and bottom plate 7. Then, through-holes 10 where chip parts 9 are nearly inscribed are made in the bottom plate 7 corresponding to intersections of a board lattice 8 set virtually on the printed circuit board 4. Therefore, light from a light source 24 passes through a through-hole 10, chip parts 9, optical fiber 21, and photodetecting element 22, so whether chip parts are present or not is detected with high precision. |
