Tungsten Boat

Description Of Tungsten Boat

Tungsten Boat is a high-purity tungsten product shaped like a boat with a groove structure. It is manufactured from high-purity tungsten sheet or plate (purity ≥99.95%) through stamping, folding, welding, or riveting processes. The boat features a central groove for holding evaporation materials and extended ends for electrode clamping and electrical connection.

Tungsten boats serve as resistance heating elements and material carriers in vacuum evaporation coating systems. When electric current passes through the boat, it generates heat through resistance, raising the temperature sufficiently to melt and evaporate the materials placed in the groove—typically metals such as aluminum, silver, gold, copper, and other low-to-medium melting point materials. The evaporated atoms then travel through the vacuum chamber and deposit onto the substrate surface, forming a thin functional film.

Thanks to tungsten’s unique physical properties—including the highest melting point among all metals (3,422°C), high density (19.1–19.3 g/cm³), extremely low vapor pressure at elevated temperatures, excellent thermal and electrical conductivity, and low thermal expansion coefficient—tungsten boats maintain structural integrity and provide stable, uniform heating even in the most demanding high-temperature vacuum environments. The high purity of the material also ensures minimal contamination of the deposited film, making tungsten boats the most commonly used evaporation source in thermal evaporation coating equipment.

Features Of Tungsten Boat

Extremely High Melting Point: With a melting point of approximately 3,422°C—the highest among all metals—tungsten boats can withstand extreme temperatures without melting or deformation.

High Density and Low Vapor Pressure: Tungsten boats offer a density of 19.1–19.3 g/cm³ and extremely low vapor pressure at elevated temperatures, ensuring minimal self-evaporation and preventing contamination of the deposited film.

Excellent High-Temperature Strength: Tungsten maintains exceptional mechanical strength and creep resistance at elevated temperatures, resisting deformation and sagging even under prolonged high-temperature operation.

Good Thermal and Electrical Conductivity: Tungsten boats provide efficient heat transfer and uniform temperature distribution across the evaporation area, ensuring stable and consistent evaporation rates.

Low Thermal Expansion Coefficient: The low coefficient of thermal expansion minimizes warping and distortion during thermal cycling, extending the service life of the boat.

Corrosion Resistance: Tungsten is highly resistant to chemical corrosion and compatible with a wide range of evaporated materials.

Applications Of Tungsten Boat

Semiconductor and Electronics Industry: Tungsten boats are widely used in semiconductor metallization processes for depositing conductive metal layers (Al, Ag, Au, Cu) onto semiconductor substrates. They are also essential in LED device electrode preparation and thin-film transistor manufacturing.

Optical Coating: Tungsten boats are employed in the production of optical coatings, including anti-reflective coatings, reflective layers, and filter coatings for lenses, mirrors, and optical instruments. Vacuum coating technology was first used in the production of optical lenses such as navigation telescope lenses.

Solar Energy and Photovoltaics: Tungsten boats are used in the deposition of thin-film solar cells and photovoltaic device electrodes.

Decorative and Functional Coating: Tungsten boats are extensively used in decorative coating applications including gold plating, consumer electronics housings, mobile phones, toys, home appliances, and various decorative items. They are also used in, anti-counterfeiting marking coatings, and reflective coatings for paper and textiles.

Vacuum Metallurgy and Research: Tungsten boats serve as heating carriers in vacuum metallurgy purification processes and are widely used in research laboratories for material evaporation experiments and thin film deposition studies.

Capacitor Metallization: Tungsten boats are used in the metallization coating of capacitors and other electronic components.

Specifications Of Tungsten Boat