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Teflon® AF provides effective circuit protection, improved dielectrics, and easy application

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Application Description

Superconductor films based on metal oxides are protected against acids in the atmosphere by solution application of 2 mm passivation coatings of DuPont™ Teflon® AF amorphous fluoropolymer resin.

Unlike conventional niobium superconductors, films pioneered by DuPont function effectively at temperatures readily achieved by cooling with liquid nitrogen or mechanical refrigeration equipment. The photo shows a sapphire wafer with a superconductive film that functions as the entire front end of a two-channel microwave receiver.

Reason for choosing Teflon® AF

Teflon® AF provided effective circuit protection, improved dielectrics and easy application.

Benefits Gained

  • Effective Protection
    Teflon® AF provides more protection against atmospheric acids and better adhesion than typical polyimide passivation coatings.

  • Durability
    Tests show the coating has good resistance to boiling water, and there has been no breakage of brittle oxide films during thermal cycling tests.

  • Easy Application
    Solutions of Teflon® AF are applied by conventional spin coating techniques to controlled thickness down to 1 Rm. They dry at 100°C (212°F) by solvent evaporation.

  • Higher Electrical Performance
    Superconductorbased devices under development gain increased velocity of propagation and reduced crosstalk, thanks to the very low dielectric constant (1.89-1.93) of Teflon® AF.