The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 2012
Filed:
Dec. 07, 2010
Hans Dohse, Sunnyvale, CA (US);
Hans Dohse, Sunnyvale, CA (US);
Maskless Lithography, Inc., San Jose, CA (US);
Abstract
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.