Coatings for complex surfaces

A system for the deposition of thin films, by magnetron sputtering technique, on the inner surface of a cavity called a substrate. The system comprises a cathode (target), consisting of the base material to be deposited, and an innovative rotating magnetic structure. Thanks to the particular configuration, the magnetic structure is unique for both the inner and outer parts of the cathode.

How does it work?

The invention originates as a solution to the technical problem of deposition by magnetron sputtering inside cavities; however, its use can be extended to all objects with complex geometry characterized by two coaxial cylinders joined at one end and which must be coated with a thin film of uniform thickness.

The invention consists of a target of the material to be deposited consisting of two concentric tubes joined together in the upper part. An innovative magnetic structure is built into the inner cavity, which allows the plasma to be confined to the inner surface of the tube with a smaller target diameter and to the outer surface of the tube with a larger diameter. The particular magnetic configuration, which varies according to the application, allows for a single plasma confinement and, by means of a mechanism that rotates the magnets, moves the plasma over the entire cathode so as to ensure high uniformity of deposition.

Applications

• quarter-wave accelerating cavities;
• tumblers and doughnut moulds;
• drums for washing machines;
• candyfloss containers;
• concrete or mortar mixer.

Advantages

• Coatings on concentric and coaxial surfaces made with greater uniformity and faster times;
• Sputtering technology (with hard, protective, anti-wear coatings, etc.) application to new product sectors that normally, due to technical difficulties, have not been developed.