| 摘要 |
PURPOSE:To enable the detection of a defective soldering point, by lighting a part to be inspected of a soldered surface of a printed circuit board to be inspected alone selectively bright. CONSTITUTION:A varying density image of a projection plate 3 lighted from a light source 1 is formed on a soldered surface of printed circuit board 7 to be inspected with a projection lens 5. The projection plate 3 is, for example, a positive plate for forming a pattern of the circuit board 7 and a light transmitting pattern formed corresponding by to the part being inspected of the board 7. Therefore, the part 8 to be inspected on the board 7 is lighted bright but the other part is made dark. To photograph the board 7, an imaging system is provided which comprises a 1-D or 2-D image sensor 11 such as CCD image sensor and a light receiving lens 9 for forming a surface image of the board 7 on an imaging surface of the sensor 11. The imaging system takes a soldered surface being moved relative to the board 7 with a moving mechanism. Thus, a defective solder point can be detected. |
