Applications
properties
|
Low pressure plasma |
Atmospheric plasma |
 |
| Advantages |
Disadvantages |
Advantages |
Disadvantages | |
Generation of plasma
-generally- |
Plasma is evenly distributed inside the plasma chamber. Chamber volume can vary from 2 to 12,000 litres. |
Complex vacuum technology. In-line plasma applications are limited. |
Plasma treatment is possible directly at the conveyor belt. In-Line suitable. No vacuum necessary. |
The treatable area is limited to approx 8 – 12 mm (plasma generation principle). More nozzles are required to treat larger surfaces. |
|
Treatment of metal |
Oxidation-sensitive objects can be treated with plasma. (e.g. H2 process gas) |
Microwave plasma can transfer the energy to the object, which then overheats. KHz does not cause overheating. |
When aluminum is treated with plasma, very thin oxide layers (passivation) can be created. |
Plasma treatment of oxidation-sensitive objects is limited. |
|
Treatment of
polymers and elastomers |
PTFE can be activated with plasma. (Etching process.) Advanced plasma processes for elastomer- and PTFE gaskets have been developed and are in use. |
For several materials (e.g. silicon) a bigger pump is required to reach the necessary process pressure. |
“Endless objects” (e.g. tubes or cables) can be treated with plasma. Very short process time. |
The plasma jet has a high temperature of 200 – 300 °C. Process parameters have to be well-aligned to the surface to avoid burning the material. (thin materials) |
|
3-D Objects |
All items in the plasma chamber are treated uniformly. Also cavities can be treated from inside. (e.g. water tanks, ignition coil) |
None known |
Local surface treatment is possible (e.g. gluing groove) |
Complex robotic technology is necessary. Treatment of surfaces with deep grooves is limited. |
|
Bulk material |
The rotary drum procedure enables uniform plasma treatment of bulk material. The quantity and volume can vary. |
Only 1/3 of the rotary drum volume can be used. |
The objects can be treated directly in-line |
The objects have to be positioned very accurately on the conveyor belt. |
|
Electronic / semiconductors |
Plasma treatment of electronic devices, printed circuit boards and semiconductors is state of the art. |
None known |
Plasma treatment of metal or indium tin oxide contacts is possibly directly before the bonding process. (e.g. LCD – TFT, chip production) |
The high temperature of the plasma jet and the reduced ability to treat surfaces with deep grooves may limit the usage of atmospheric plasma in the electronic industry. |
|
Coating process |
The coating layers are identical und uniform. Many PECVD and PVD processes have been developed and are in use. |
Plasma chamber can be contaminated by coating material. |
No industrial uses known yet. |
No industrial uses known yet. |
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