| 摘要 |
PURPOSE:To find abnormality in the surface of a printed circuit board to be inspected and to improve the reliability of inspection by projecting a homogeneous inspection light beam which is easily absorbed by the surface to be inspected upon the surface in the dark and detecting the quantity of its reflected light. CONSTITUTION:An inspection light emitting device 11 emits a light beam which is easily absorbed by green of a green coat surface 2 as the inspection light beam 1. This inspection light beam 11 is projected over the entire area of the green coat surface by a projecting device 12. If there is a solder bridge 2 above the green coat surface 2, almost none of the inspection light beam 11 is absorbed by the solder bridge 6 and the light is reflected, so the reflected light beam 12 is larger in quantity than when impinging on the green coat. Therefore, it is judged on the basis of the certain quantity of reflected light that there is no abnormality in case the light is smaller than said quantity or abnormality when larger. A mirror is driven under support control, so the position of the abnormality is easily found. |
