Evaporation Tungsten Boat
- High purity W ≥ 99.95% with density 19.1–19.3 g/cm³
- Highest melting point among all metals — 3422°C ensures structural stability under extreme heat
- Extremely low vapor pressure minimizes self-evaporation and film contamination
- Excellent thermal and electrical conductivity for uniform heating
- Available in multiple types: stamped, folded, welded, riveted
- Customizable: length 50–1000mm, width 10–500mm, thickness 0.2–5.0mm
Description Of Evaporation Tungsten Boat
Evaporation Tungsten Boat, also known as tungsten boat, tungsten evaporation boat, coated tungsten boat, or thermal evaporation tungsten boat, is a high-purity boat-shaped resistive heating element used in vacuum thermal evaporation coating processes. It is manufactured from high-purity tungsten sheet (purity ≥99.95%) through precise stamping, bending, welding, or riveting processes. The boat features a boat-shaped structure with a central recess designed to hold evaporation materials, while both ends extend outward as electrode connection zones for stable electrification and highly efficient heating.
When electric current passes through the boat, it generates heat through resistance, rapidly raising the temperature to melt and vaporize the metal materials (such as aluminum, silver, gold, copper, etc.) placed in the recess. In a high-vacuum environment (typically ≤10⁻³ Pa), the evaporated particles migrate linearly and deposit onto the substrate surface, forming a uniform functional thin film. This process belongs to the thermal evaporation technology system within physical vapor deposition (PVD).
The exceptional high-temperature performance of evaporation tungsten boat originates from the physical properties of tungsten itself. With the highest melting point among all metals (~3,422°C), tungsten boats can operate stably for long periods at temperatures above 1,800°C without significant softening or deformation. The high density (>19.1 g/cm³) and extremely low vapor pressure ensure minimal self-volatilization at elevated temperatures, effectively reducing the risk of thin-film contamination. The excellent electrical and thermal conductivity, combined with a low coefficient of thermal expansion, further enhances heating efficiency and structural integrity during thermal cycles.
Features Of Evaporation Tungsten Boat
Semiconductor and Electronics Industry: Evaporation tungsten boats are widely used in semiconductor metallization coating processes for depositing conductive metal layers (Al, Ag, Au, Cu) onto semiconductor substrates. They are also essential in LED chip electrode fabrication and thin-film transistor manufacturing.
Optical Coating: Tungsten boats are employed in the production of optical thin films, including anti-reflective coatings, reflective layers, and filter coatings for lenses, mirrors, and optical instruments. Vacuum coating technology was first applied to optical lenses such as navigation telescope lenses.
Solar Energy and Photovoltaics: Tungsten boats are used in solar cell thin-film deposition and photovoltaic device electrode preparation.
Decorative and Functional Coating: Tungsten boats are extensively used in decorative coating applications including gold plating, consumer electronics housings, mobile phones, home appliances, and various decorative items. They are also used in metallization coating, anti-counterfeiting marking, and surface modification.
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 and Electronic Component Manufacturing: Tungsten boats are used in the metallization coating of capacitors and other electronic components.
Usage Precautions and Limitations Of Evaporation Tungsten Boat
Atmosphere Requirements: Tungsten oxidizes rapidly at elevated temperatures in the presence of oxygen. Tungsten boats must be used exclusively in high-vacuum environments (typically ≤10⁻³ Pa) or inert gas atmospheres to prevent oxidation and ensure optimal performance.
Deformation During Use: Due to the thin wall thickness and extremely high operating temperatures, tungsten boats are prone to deformation during use—typically the boat walls bend inward. If deformation becomes severe, the boat should be replaced.
Embrittlement After Use: Tungsten becomes brittle after high-temperature exposure. Used boats should not be bent or mechanically stressed, as they may fracture.
Gradual Heating: To prevent cracking, the boat must be heated gradually. Slow voltage increase is recommended during the initial heating stage.
Handling and Storage: Tungsten boats should be handled with care to avoid surface contamination or mechanical damage. They should be stored in a dry, clean environment.
Compatibility Verification: Before integrating tungsten boats into your equipment, verify that the model, dimensions, and shape meet your specific equipment electrode spacing and process requirements.
Specifications Of Evaporation Tungsten Boat