When energy is continuously supplied to a matter, the temperature of the matter increases and it passes from solid state to liquid and finally to gaseous state. If the energy supply continues, the existing atomic shell disintegrates and charged particles are created (negatively charged electrons and positively charged ions). This mixture is referred to as plasma or the “fourth state of matter”.
In short: Change of the aggregate status under energy supply:
solid ⇒ liquid ⇒ gaseous ⇒ plasma
Natural plasma occurs for example in lightning, polar lights, flames, and the sun. Artificially created plasma is found in neon tubes, welding processes and in flash bulbs, among others.
Plasma is used in applications where it is important to combine materials or to specifically change their surface properties. This future-oriented technology allows for modification of a wide range of surfaces. Thus, many different applications are feasible, such as
- ultrafine cleaningof small and micro-components
- activationof plastic surfaces before bonding, painting etc.
- Surface etchingand partial removal of various materials such as PTFE, photoresist etc.
- Coating of componentswith PTFE-like coats, barrier coats, hydrophobic or hydrophilic coats, friction-reducing coats etc.
Nowadays, plasma technology is established in almost all sectors of industry, and new applications are being developed constantly.