| 摘要 |
<p>PURPOSE:To examine the apperance automatically and highly accurately by controlling the depth of field and the focus position so as to make the imaging position same even though the focus surface position of an object to examine is changed. CONSTITUTION:When an object to examine is a semiconductor intermediate product a wire bonding has been applied, for example, and the height of the wire is examined, the focus of the wire part is controlled to fit to the image pickup surface of a camera 2 by moving the examining part up and down by a driver 15 to be a focus controll means. And the depth of field is controlled 9 by selecting a diameter diaphragm window of either the diaphragem window 13a or 13b of a depth of field control means 3. When the diameter of the diaphragm widow is made smaller, the depth of field is made wider. In such a way, the image of the wire is photographed by the camera 2 in order, and each specific amount of brightness distribution is picked up 10. The specific amount are compared by a deciding member 11 so as to decide a height defect of the images. Consequently, even though the focus surface position of the wire is changed, the imaging position of the camera 2 is not changed.</p> |
