Development History of Vacuum Coating Technology

In 1852, W.R. Grove discovered the sputtering phenomenon during vacuum discharge experiments, laying the theoretical foundation of sputter coating. In 1857, Michael Faraday accomplished the earliest intentional vacuum thin-film deposition by evaporating materials under vacuum conditions. Thomas Edison filed a vacuum evaporation coating patent in 1884 for phonograph component production, marking the first industrial-oriented vacuum coating attempt.

For nearly 80 years afterward, relevant technologies stayed in lab research due to immature vacuum pumping equipment and unstable high-vacuum environment. Until the 1930s, the invention of oil diffusion pumps drastically upgraded vacuum acquisition capability and pushed vacuum coating from theory toward practical use.

From the mid-1930s, thermal vacuum evaporation was first commercialized: anti-reflection coatings for optical lenses, aluminum reflective films for lamp shells and mirror metallization were put into batch production. WWII boosted the industry sharply: massive demand for precision optical parts for military equipment accelerated the popularization of vacuum evaporation technology worldwide, and complete vacuum evaporation production lines gradually took shape in Europe and the US. By the 1950s, evaporation coating dominated optical and packaging metallization fields, while traditional chemical wet coating was gradually replaced in high-precision scenarios.

1966 witnessed the formal definition of PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) in the monograph Vapor Deposition, officially classifying mainstream vacuum coating categories. In 1967, the ion plating core patent was granted to Mattox, enriching the PVD process system.

Magnetron sputtering, the milestone innovation, was developed and widely commercialized from the 1970s to 1980s. Compared with early triode sputtering, magnetron sputtering features higher deposition speed, denser coating and lower substrate temperature, making it applicable to plastics, aluminum alloy and fragile base materials. Unbalanced magnetron sputtering emerged in 1986 to further improve coating adhesion and uniformity. Meanwhile, CVD matured for high-temperature hard coating and semiconductor wafer coating applications.

Vacuum coating stepped into consumer electronics, hardware decoration, automotive parts and optical film industries. Arc PVD for metal decorative coating (gold, black, rose-gold finish) and AF anti-fingerprint coating became standard processes for mobile phone housings, stainless steel components and digital products. Roll-to-roll continuous vacuum sputtering was applied to flexible film, touch panel and EMI shielding film mass production, greatly lifting production efficiency. Domestic vacuum coating manufacturing developed rapidly in China to support the booming electronics supply chain.

Modern vacuum coating evolves toward intelligent automation, low-carbon and multi-functional composite coating: integrated PVD equipment with automatic loading/unloading, real-time film thickness monitoring prevails in factories. New functional coatings including anti-corrosion, wear-resistant, antibacterial and ultra-thin shielding films keep emerging. R&D focuses on energy-saving coating processes and non-toxic target materials to satisfy stricter global environmental protection standards.