Can a vertical tube heat treatment electric furnace be coated with film?

Vertical tube type heat treatment electric furnace can be used for coating, especially chemical vapor deposition (CVD) coating process, thanks to its unique structural design and functional characteristics. The specific analysis is as follows:

1. The core advantages of vertical tube furnace in coating process
Vertical design ensures uniformity
The vertical structure allows the material to be vertically distributed in the furnace, and with the help of fluidized bed technology, it can ensure sufficient contact between the reaction gas and the material surface, eliminating dead corners in the reaction. For example, in crystalline silicon substrate coating, vertically arranged substrates can uniformly adsorb the precursor of vapor deposition, forming a thin film with uniform thickness.
Multi atmosphere control ability
The vertical tube furnace can be pre evacuated to a high vacuum degree (such as 10 ⁻ ³ Pa) and filled with protective or reactive gases such as hydrogen, argon, nitrogen, etc. In CVD coating, the deposition of thin films with different compositions can be achieved by precisely controlling the gas flow rate and ratio. For example, in the development of carbon nanotubes, a mixture of methane and hydrogen gas can be introduced to grow high-quality carbon nanotubes on the surface of the catalyst.
Adaptability to high temperature environments
The maximum temperature of high-end vertical tube furnaces can reach 1600 ℃ or even higher, meeting the needs of various coating processes. For example, in diffusion welding of metal materials, high temperature environment can promote the diffusion between metal atoms, forming a dense welding layer; In the preparation of semiconductor materials, high temperature environment can ensure excellent crystallinity and electrical properties of thin films.

2. Typical coating application scenarios
Semiconductor material coating
Vertical tube furnace can be used for processes such as oxidation, vapor deposition, and deposition of silicon chips. For example, depositing a silicon dioxide film on the surface of a silicon wafer using CVD technology can serve as an insulating or protective layer, improving the performance and stability of semiconductor devices.
Surface modification of metal materials
Coating the surface of metal parts can improve their wear resistance, corrosion resistance, and hardness. For example, depositing titanium nitride film on the surface of titanium alloy through a vertical tube furnace can significantly improve its surface hardness and wear resistance, and extend its service life.
Preparation of new energy materials
In the preparation of positive and negative electrode materials for lithium batteries, a vertical tube furnace can be used to coat a conductive or lithium conducting thin film on the surface of the material to improve its electrochemical performance. For example, coating a carbon layer on the surface of lithium iron phosphate material can improve its conductivity and cycling stability.

3. Operation points and precautions
temperature control accuracy
The coating process requires extremely high temperature control, and temperature fluctuations may affect the crystallinity and compositional uniformity of the film. Vertical tube furnaces need to be equipped with high-precision temperature control systems (such as PID automatic control) to ensure temperature fluctuation range.
Atmosphere purity guarantee
During the coating process, impurities in the atmosphere may contaminate the surface of the film and affect its performance. Vertical tube furnaces require pre vacuuming and multiple gas replacements to ensure that the purity of the atmosphere inside the furnace meets the process requirements. For example, in CVD coating, the oxygen content inside the furnace needs to be controlled.
Safety operation standards
When the temperature of the furnace body is higher than 1000 ℃, the furnace tube cannot be in a vacuum state and must be maintained at normal pressure to prevent the furnace tube from breaking.
It is not recommended to close the exhaust valve and inlet valve at the flange end of the furnace tube during the heating process. If they need to be closed, always pay attention to the pressure reading to ensure that the absolute pressure does not exceed 0.02 MPa.