APS Plasma Assisted Processes

Siltint’s advanced APS plasma assisted processes ensure that the coatings are environmentally stable and that higher surface damage thresholds are achieved.  Additionally, this technology enables the deposition of coatings onto temperature sensitive substrates such as polycarbonate or very thin plastics.

Key advantages of APS Plasma Assisted Coatings

• low temperature vacuum deposition (<60^o C)
• no damage to bonded lenses or higher index materials
• dense thin film layers for robust coatings
• uniform refractive index in the layers
• low absorption provides greater clarity and transmission
• The “cold” APS process also allows fragile substrates to be coated – a recent process has applied a 22 layer filter to 130 µm plastic

Evaporation in conventional vacuum chambers requires the substrates to be heated to about 300° C before deposition starts. The heat is required to bond the evaporated materials to the substrate.

However, lower temperature coating has become important as more sophisticated lens materials are introduced which are sensitive to processing temperatures. The Leybold APS argon gas plasma system utilises low temperature high-powered plasma during the deposition of carefully selected dielectric materials. The argon gas plasma source adds energy to the process without creating heat or thermal stress to the substrates.

APS technology produces dense, environmentally stable films and the ability to deposit high performance coatings in the UV, visible and near infrared spectra onto glass, silicon and fragile plastics.

SEM photo of the columnar layer structure using conventional evaporation

The columnar structure created by conventional evaporation can trap dust and grease in an operating environment and are more susceptible to surface damage.