Maskless Lithography, Inc.

Chime Ball Technology Co., Ltd.

Hans Dohse

A method and system for alignment of a tool to a workpiece in a continuous or discontinuous material flow are disclosed. The workpiece may be a portion of a web of material. An imaging system captures first and second images of the workpiece at first and second occasions respectively. Microscopic native features of the workpiece are selected, detected, tracked and/or compared in the first and second images. Based on the correspondence between, tracking or relative displacement of features as captured in the first and second images, an alignment to the workpiece is controlled. In embodiments, the workpiece and a tool, a projected image or a pattern to be imparted to the workpiece by a lithography or photolithography apparatus are aligned based upon positioning information determined from an analysis of correlated features or texture in the images. Positioning information may include a positioning error or a distortion indication.

Alignment system for various materials and material flows

An alignment system for optical lithography uses cameras fixed to a movable stage and to a lithography unit to view unique microscopic non-uniformities that are inherent to the surface of a work piece, e.g., metal or ceramic microcrystalline grains, for position referencing. Stage cameras image two sites on the work piece through windows in the stage to establish original position templates. After the work piece has been repositioned, e.g., reversed topside-down, the same two sites are again viewed and template matching establishes the transformed coordinates of the work piece, e.g. by a lithography unit camera under which the stage moves to approximate site locations. Two corner cameras can serve as a coarse positioning mechanism. The alignment system is particular useful for backside alignment in printed circuit board lithography.

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Sunnyvale, CA, United States of America

Hans Dohse