| 摘要 |
PURPOSE:To enable position detection for a variety of substrates by regarding a coordinate position, based upon coordinate values of two integral values which are judged to match scribing line widths in an X and a Y direction, as the position of the angle in the crossing area of the scribing lines. CONSTITUTION:An enlarged gradational image of the scribing line crossing area of a substrate W which is picked up by a television camera 6 is inputted to an image processing unit 7. The image which is inputted to the unit 7 is an image which is photographed through a downward lighting microscopy opti cal system, so the gradation value of the edges of the scribing lines on the substrate W is small. Then the edges of the scribing lines slant to the substrate surface because of a step due to the high-low difference between the areas of the scribing lines on the substrate surface and a pattern area. Therefore, light which is projected from an objective 2 and irradiates the substrate W is reflected off the entrance pupil of the lens 2, so that the light does not reach the camera 6. |
