Patent ID: 8212869

Claim:
A substrate inspection method using a substrate inspection system including a camera provided with an image forming device for forming an image of a substrate to be inspected to be inspected, and a table for supporting the substrate to be inspected for photographing by the camera, said substrate inspection method comprising the steps of: determining coordinates of reference points represented by known coordinates in a three-dimensional world coordinate system in a jig mounted on the table in an pixel image coordinate system specified by pixels arranged in a matrix in the image forming device by forming an image of the jig by the camera; transforming the coordinates of the reference points in the pixel image coordinate system on the basis of the length and width of the pixels into coordinates in a two-dimensional image coordinate system on an image formed by the camera; transforming the coordinates of the reference points in the two-dimensional image coordinate system into coordinates in a three-dimensional camera coordinate system on the camera by correcting the coordinates of the reference points by using device parameters including parameters of an optical system included in the camera; calculating world-camera coordinate transformation parameters including displacements of the camera coordinate system from the world coordinate system in an X-, a Y- and a Z-direction and angular displacements about an X-, a Y- and a Z-axis on the basis of coordinates of at least six reference points in the camera coordinate system determined by the preceding steps, coordinates of the reference points in the world coordinate system and a world-camera coordinate transformation expression; obtaining image data in the pixel image coordinate system by photographing a substrate to be inspected placed on the table; transforming the image data in the pixel image coordinate system obtained by the preceding step into image data in the two-dimensional image coordinate system on the basis of the length and width of the pixels, transforming the image data in the two-dimensional image coordinate system into image data in the camera coordinate system on the basis of the device parameters, and transforming the image data in the camera coordinate system in the camera coordinate system into image data in the world coordinate system by using the camera-world coordinate transformation expression and the transformation parameters; and inspecting the substrate to be inspected on the basis of the image data in the world coordinate system.