Improved AR coating reflection color uniformity and stability using multiple anodes and fuzzy logic control in DC reactive sputter coating

摘要

DC reactive magnetron sputter techniques have been developed for the application of antireflection (AR) coatings to plastic ophthalmic lenses. The method described here uses the Deposition Sciences Inc. (DSI) Microdyn™ process in which the lenses are mounted on a spinning drum adjacent to two 40" long planar magnetron cathodes. Improvement in deposition uniformity along the length of the cathodes was accomplished by the use of multiple active anodes. Improvement in run to run stability was accomplished by use of fuzzy logic control techniques. Details of this Multiple-Anode Fuzzy-Logic (MAFL) process will be discussed in relation to the significant improvement in control of reflectance color of anti-reflection coated eyeglass lenses. For a specific anti-reflection coating, control of color coordinate a~* was improved by a factor of 2.5 and b~* by a factor of 5.0.