Method for aligning two objects, method for detecting superimposing state of two objects, and apparatus for aligning two objects

A method for moving a main chuck on which first objects are set in X, Y, Z, and θ directions to align the first objects with second objects arranged above the first objects, the method comprising:

• (a) photographing the second objects through second photographing means to obtain second photographed images;
• (b) displaying second virtual data images in a second image data area on a monitor screen of a display device on the basis of the second photographed images of the second objects;
• (c) allowing an optical axis of the second photographing means to match an optical axis of first movable photographing means to obtain a reference position of the main chuck;
• (d) moving the main chuck to align the first objects with the first photographing means and then photographing the first objects through the first photographing means to obtain first photographed images;
• (e) displaying first virtual data images of the first photographed images in a first image data area on the monitor screen of the display device on the basis of design data of the first objects;
• (f) relatively moving the first virtual data images and the second virtual data images on the monitor screen to superimpose both the virtual data images on each other;
• and
• (g) determining a position where both the virtual data images are most fitly superimposed on each other as an alignment position of the first and second objects.