| 摘要 |
An optical system for inspecting bonding wires (70) on a semiconductor has a camera (1), focal length and depth adjusting means (2), an illumination device (4) for irradiating brilliantly a desired portion of an inspection object (7) with an illumination light. The focal length and depth adjusting means (2) comprises a plurality of glass plates (21, 22, ... 24) each having a different focal length and depth, and each bonding wire (70) is inspected at a plurality of levels (F1, F2, F3) in height position of the wire (70) and at a plurality of portions (P, Q) thereof in its longitudinal direction to make a comparison between focal point evaluation quantities (E) at each detected position whereby wiring defects can be detected. |
