Scan head, an appearance inspection method and an appearance inspection apparatus using the same

摘要

An appearance inspection apparatus for inspecting a surface of a printed circuit board requires high inspection accuracy and inspection time reduction. To this end, the apparatus has a scan head that scans an object under inspection and generates image data of the surface of the object. The scan head includes a vertical light source which projects light on the surface from right above the object and a side light source which projects light sidelong on the surface. A lenticular sheet is provided between the vertical light source and the object in order to adjust the vertical light and improve the inspection accuracy in a vertical light test. In a side light test, light sources other than the central part in the vertical light source is turned on and an auxiliary light is projected along with the side light, so that the dynamic range for the inspection can increase.