Dual rotary magnetron source for web coating

High material utilization and long target life make rotary cylindrical sources ideal for coating of rolled substrates. Here we consider a process in which two rotary cylindrical targets are employed to coat a web substrate conformed on a continuously rotating drum.

Two 120-cm-long cylindrical and rotary targets, as in Case 13S, are employed here for coating of the 1-meter-wide web substrate. The magnets of the cathodes are rotated by a few degrees towards the drum axis to gain slightly in vapor collection and uniformity. 

    Similar to linear motions, the uncorrected thickness distribution across the substrate width exhibits a bow curve, as shown by the red points in the diagram below. The uncorrected distribution has a non-uniformity of +/-3.5%. 

To improve the thickness uniformity, a correction mask pair can be installed. V-Grade 5S allows you to create a mask shape, free hand, in a trial-and-error process to obtain one that suppresses the non-uniformity; for further optimization you can engage the automated mask optimizer (a standard feature of V-Grade 5S). With a mask optimized in V-Grade 5S, the thickness non-uniformity is reduced to +/-0.31%, shown by the blue points in the above diagram.  One can achieve excellent thickness uniformity while blocking the least amount of material vapor, which means the lowest material waste and highest deposition rate.