| 摘要 |
PURPOSE:To improve an illuminating degree of a part to be inspected and to enhance an inspecting accuracy by altering an illumination angle of vertical illuminating means to a certain degree by a motor-driven diaphragm. CONSTITUTION:When a ball 5a bonded to a pad 2 is, for example, inspected, an aperture diameter of a motor-driven diaphragm 50 is reduced to make illumination of vertical illumination means 38 in parallel. Then, a quantity of an incident reflected light of the ball 5a is reduced, and a quantity of the incident light to an objective lens group 24 is increased in a mirror surface of the periphery of the ball 5. Accordingly, the shape of the ball 5a is projected to be black. On the other hand, when a crescent 5b bonded to a lead 4 is inspected, the crescent 5b is, in the case illuminated by the parallel beam, less at random reflection than that of the lead 4, and hence projected to be dark so that an irregularity in brightness occurs due to an uneven part of the lead 4. Then, when the aperture diameter of the diaphragm 50 is increased to provide an angle in the illumination to the crescent 5b, the irregularity in the brightness of the lead can be eliminated. |
