Temperature control of metal strip during high-rate vacuum coating

• Novel equipment for effective cooling of metal strips in high-rate vacuum coating was developed.
• Demonstrated heat transfer coefficients amount up to 1000 W/m2 K.
• The cooling effect corresponds to heat input during high-rate physical vapor deposition.
• A controlled thermal substrate management for metal strips becomes possible.

Electron beam evaporation with deposition rates of hundreds of nanometer per second is predestined to fit large throughput. In a few cases, high-rate vacuum depositions demand effective cooling of the substrate to exploit their potential, otherwise substrate or layer temperature represents limiting factors. Therefore a new kind of cooling equipment for vacuum coating of metal strips was developed. As a result, the practical realized heat transfer coefficient (HTC) was increased from 50 W/m2 K for common cooling drums up to 1000 W/m2 K. The demonstrated heat transfer coefficients describe a distinctive performance increase compared to known state of the art. For the first time, a 10 μm aluminum high-rate deposition was realized without any alloying with steel strip. Extensions concerning the deposition rate or deposition of thick layers onto thin metal foils become feasible.