What Is an Atmospheric Pressure Plasma Device?
Atmospheric pressure plasma devices are devices that use plasma discharge to remove organic matter and oxides.
They are characterized by the fact that they consist only of reaction gas for plasma generation and a power supply, and do not require a decompression tank. Because they can remove organic films on the surface of polymer materials and oxides on metal surfaces, they are widely used not only for industrial applications but also for academic research. Compact devices have also been developed and are used in a variety of fields.
Specifically, they are used for sterilization of medical instruments, sterilization in food processing plants, and surface treatment in semiconductor manufacturing processes. Furthermore, environmental issues are also being addressed, and atmospheric pressure plasma devices are being used to develop technologies for purifying exhaust gases and wastewater.
Uses of Atmospheric Pressure Plasma Devices
Atmospheric pressure plasma device can modify the surface of resins, films, and polymer materials. Surface modification can be performed at high speed and without damaging the surface.
They are widely used in the manufacture of semiconductors, electronic components, plastics, and glass products. Specifically, surface cleaning using reactions with plasma and changes in the composition of polymer surfaces can be expected to improve hydrophilicity.
In addition, even materials such as polyethylene and polypropylene can be bonded with adhesives (urethane or epoxy-based) to increase their bonding strength. For this reason, atmospheric pressure plasma device is also used for products such as automobile parts and medical devices, where adhesive strength is required.
Principle of Atmospheric Pressure Plasma Devices
An atmospheric pressure plasma device uses a high-frequency pulse power supply to generate a plasma discharge, and the active species such as electrons and ions in the plasma are used for surface modification and cleaning.
Plasma is the fourth state of matter and is a high-energy state. In plasma, electrons and remaining ions are mixed together as a result of the ionization phenomena in which electrons are ejected from atoms, but the overall charge distribution is maintained as neutral.
In atmospheric pressure plasma device, active species in the plasma cause chemical reactions on surfaces, enabling surface modification and cleaning. For example, when oxygen plasma is generated, it bonds with the carbon atoms that make up the resin and desorbs them from the surface as CO2. This chemical reaction can be used to clean and modify the surface of resins, films, and polymer materials.
Atmospheric pressure plasma device is also used in the manufacture of semiconductors, electronic components, plastics, and glass products. Surface cleaning and changes in the composition of polymer surfaces using reactions with plasma are expected to improve hydrophilicity and enhance adhesive strength.
Atmospheric pressure plasma devices are low-temperature plasmas that can generate plasma at relatively low temperatures compared to thermal plasmas, which are in a high-temperature state, and can be generated by using a high-frequency pulse power supply.
Types of Atmospheric Pressure Plasma Devices
There are two main types of atmospheric pressure plasma devices: corona discharge plasma devices and microwave plasma devices
1. Corona Discharge Plasma Device
Corona discharge plasma devices are based on plasma generated using a high-frequency power supply. By applying a high-frequency voltage between the electrodes, plasma is discharged, and surface modification and cleaning are performed through chemical reactions with the reaction gas. It is characterized by low temperatures and is effective for polymer materials such as resins and films.
2. Microwave Plasma System
Microwave plasma systems use microwaves to generate plasma. By pouring in a reaction gas and applying a high-frequency electric field, the microwaves are absorbed by the reaction gas and plasma is generated. It can generate high-temperature plasma, which is used for high-resolution surface modification and thin-film formation of metals and ceramics.