Why vacuum coating requires a gas mass flow controller

sales01@cxflowmeter.com

Why vacuum coating needs to use gas mass flow controller

        Fluctuations in pressure within the vacuum chamber cause uneven coating and poor repeatability. While the mass flow controller controls

 the reaction gas, a pressure controller is used to control the pressure of the inert gas in the chamber, thereby improving the final plasma

 vapor deposition (PVD) result. The vacuum coating process is usually carried out in a negative pressure sealed chamber. The reason why 

the vacuum is drawn is that the ambient gas will interfere with the reaction process between the substances involved in the coating. In a 

vacuum environment, the vaporized metal, ionized molecules, plasma reaction compounds and other coatings can interact with other 

materials to be plated. The surface blends.

     To put it simply, a vacuum coating system usually consists of two main parts: the first is a vacuum chamber connected to a vacuum pump. 

A throttle valve is usually used to adjust the vacuum level and control shutdown to prevent leakage. The other part is the gas source. 

The gas is input into the vacuum chamber after passing through the mass flow controller to form a gas density level suitable for coating. 

Some of them are non-reactive inert gases, which are only used to maintain the negative pressure environment of the vacuum chamber 

and will not have any impact on the concentration of chemical substances participating in the reaction. Next comes the reactive gases, 

such as oxygen used in the oxidation coating process. Some vacuum coating processes use non-reactive gases as carrier gases or to 

dilute reactive gases. The coating material can be vaporized metal that has been ionized through melting and electric field devices. 

In some systems, a portion of the “purge gas” is used to “clean” the process chamber after the reaction.

       The coating principles are also varied. Some are relatively conservative, such as allowing the vaporized metal to slowly precipitate 

on the surface to be plated, while others include sol, which fuses with the surface to be plated by forming a plasma vapor cloud arc, 

or by charging the plated object to make it target. The ions create adsorption force.

Solution:

Use our gas mass flow controllers to control the pressure of the inert gas filled into the vacuum chamber to create a well-controlled coating 

environment. An external vacuum gauge connected directly to the reaction chamber measures the continuous process pressure. This 

pressure reading is transmitted via an analog signal to the pressure controller and displayed.

       The flow rate of reaction gases entering the chamber is controlled by a mass flow controller. Because the above-mentioned pressure 

controller can measure the pressure in the chamber and adjust the process pressure in real time by adjusting the content of non-reactive 

gases, thereby forming a coating environment in the chamber that is most conducive to deposition.

If you also want to know more about pressure vacuum gauges and gas flow controllers, how to select and quote, 

please contact winny:sales01@cxflowmeter.com