Diffusion Pump Oil in the Vacuum Coating Industry

Scenario 1: Optical Coating (Anti-Reflective Coatings, Reflective Coatings)
Requirements: Vacuum levels of 10⁻³ to 10⁻⁵ Pa are required to ensure uniform deposition of coating particles (e.g., TiO₂, SiO₂) and prevent oxidation or contamination.
Oil Type: Silicone oil or polyphenyl ether (excellent thermal stability, resistant to decomposition under prolonged high temperatures, minimizing hydrocarbon contamination of the film).

Scenario 2: Functional Coatings (Semiconductor Packaging Coatings, Automotive Glass Heat-Insulating Films)
Requirements: Balancing high vacuum with continuous production; oil must have strong contamination resistance and a long service life.
Oil Type: Perfluoropolyether (PFPE) (chemically resistant, suitable for environments with metal vapors).

3. Scientific Research and High-End Instruments

Scenario 1: Surface Analysis Instruments (XPS, SEM, TEM)
Requirements: Vacuum levels of 10⁻⁶ to 10⁻¹⁰ Pa are necessary to prevent oil vapor interference with surface signal detection.
Oil Type: Ultra-high vacuum silicone oil (e.g., molecularly distilled DC-705) or polyphenyl ether (low volatility, suitable for long-term stable operation).

Scenario 2: Nuclear Fusion Devices (Tokamak)
Requirements: Extremely stringent vacuum conditions (<10⁻⁸ Pa); oil must withstand high-energy particle bombardment and extreme temperatures.
Oil Type: Perfluoropolyether (highly chemically inert, non-reactive with plasma).