| 摘要 |
PURPOSE:To enable inspection of polarity without being affected by a blur of an indicative character and printing precision by detecting existence or nonexistence of an indentation inside an inspection window from the existence or nonexistence of a shadow part by illumination from an oblique direction. CONSTITUTION:An illuminator 11 irradiates surface package IC 12, an object of inspection, from an oblique direction. A camera 13 fitted above the IC 12 outputs a gradation density image signal (a) and this is converted into binary- coded signals (b) of '1' and '0' corresponding to a bright part and a dark part respectively by a binary-coding circuit 14. A window generating circuit 15 generates an inspection area of dimensions set beforehand for the signal (b), at the position of an indentation existing on the upper surface of the IC 12 mounted in a normal direction, and outputs an inner-window binary-coded image signal (c). A measuring circuit 16 measures the area of '0' of the signal (c) and outputs an inner-window area signal (d). A determining circuit 17 compares the measured area with an area set beforehand and determines the former as defective when it is larger than the latter. According to this constitution, inspection of polarity can be executed without being disturbed by an indicative character and printing precision. |
