Scribed Alignment Mark
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07
Where accurate alignment is required of parts with an edge that is not clear, an automatic edge detector is employed to define an edge and a laser is operated to scribe an alignment mark parallel and perpendicular to the defined edge. Specifically, a substrate 10, having an edge with which future processing steps are to be aligned, is placed on an X, Y table 11. An edge detector 12, which detects different reflectance characteristics, is driven by processor 13 in cooperation with X, Y stage drive 14 to determine on a statistical basis the actual edge of substrate 10. When the edge is determined, the stage drive is stepped and the substrate driven under a laser 15 to cause the laser to scribe an alignment mark parallel to the determined edge. This alignment mark can then be used for all subsequent alignments.