Jämförelse
| Applications properties |
Low pressure plasma | Atmospheric plasma |  |
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| Advantages | Disadvantages | Advantages | Disadvantages | ||
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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. | |
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Treatment of metal
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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. | |
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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) | |
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3-D Objects
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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. | |
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Bulk material
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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. | |
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Electronic / semiconductors
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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. | |
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Coating process
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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. | |