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FAQ - LOW PRESSURE PLASMA
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[ ANSWERS TO FREQUENTLY ASKED QUESTIONS ]
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- Within which pressure range can be worked?
- What should be available for a plasma machine (connections...)?
- What means plasmaetcher / plasma etcher?
- What means plasmacleaner / plasma cleaner?
- What means plasmaasher / plasma asher?
- What is plasma?
- What is plasma etching?
- What is plasma activation?
- Usable kinds of gas?
- Up to which layer strength can be etched?
- Possible materials for plasma treatment:
- Is it possible to treat foils?
- How much can the surface be changed or improved?
- Do toxic or inflammable exhaust gases will be developed?
- Do raditions injurious to health develop?
- Can plasma also be used with material-combined parts?
- Can parts be also partly etched or treated?
- Application possiblities:
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[ Within which pressure range can be worked? ]
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The working pressure range is approx. 0,05 to 2 mbar. |
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[ What should be available for a plasma machine (connections...)? ]
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For small machines it is necessary to have a voltage supply of 230 V and adeparture for exhaust gases of the vacuum pump. Larger machines need a voltage supply of 400 V, a compressed-air-connection with
5-6 bar and also an exhaust tube. |
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[ What means plasmaetcher / plasma etcher? ]
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Plasma systems are also known as "plasmaetcher / plasma etcher". With this systems it is possible to etch different surfaces. |
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[ What means plasmacleaner / plasma cleaner? ]
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Plasma systems are also known as "plasmacleaner / plasma cleaner". With this systems it is possible to clean different kinds of surfaces. |
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[ What means plasmaasher / plasma asher? ]
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Plasma systems are also known as "plasmaasher / plasma asher". With this plasma systems it is also possible to remove photoresists for example from silicon wafers. |
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[ What is plasma? ]
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Plasma is an ionized gas. This means that neutral gas atoms are split into ions and electrons. Energy must be supplied to split neutral gases. Thies energy is supplied to the plasma with the aid of electrical fields. Direct voltage sources or alternating voltage sources can be used to iguite the plasma. The pressure range below approx. 10 mbar are designated as low pressure plasma. |
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[ What is plasma etching? ]
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With longer process times (longer than approx. 5 minutes) material is removed from the surface. The surface will be structured and increased by the etching. Therefore that a better bonding of adhesives and painting systems is possible. This application is limited on the plastic parts, elastomers, semi-conductors and some metals. |
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[ What is plasma activation? ]
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Plasma activation is the formation of radical positions at the surface. Adhesives and painting systems can be better bonded. The process times are between 1-5 minutes. |
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[ Usable kinds of gas? ]
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- Oxygen
- Hydrogen
- Argon
- Nitrogen
- Fluor containing gases and their mixtures |
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[ Up to which layer strength can be etched? ]
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The etching rate depends on the material, power time and the process gas. The etching rates are between 10 and 100 µ per hour. |
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[ Possible materials for plasma treatment: ]
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Normally there is no restricion. It is decisive that the materials which should be treated have no or only few outgassing (vacuum fitness). |
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[ Is it possible to treat foils? ]
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Generally it is possible to treat foils. But for this application it is necessary to have a more comlex equipment technique. During the plasma process the foils have to be reeled from role to role. |
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[ How much can the surface be changed or improved? ]
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Principally will the surface tension increase by the plasma treatment. The surface becomes better wettable (see also point 9). |
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[ Do toxic or inflammable exhaust gases will be developed? ]
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Because of working in the vacuum is the process gas thoughput very small. So only very small emissions are build. During the operation the pump system will be rinsed. So flammable gases are thinned below the explosion limit and therefore not inflammable. |
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[ Do raditions injurious to health develop? ]
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The developing raditions in the plasma chamber are absorbed and not delivered into the area. There is no danger. |
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[ Can plasma also be used with material-combined parts? ]
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Material-combined parts can also be plasma treated (see also point 7). |
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[ Can parts be also partly etched or treated? ]
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The surface can be protected against the plasma treatment by a suitable masking (it is also partial possible) (e.g. for plastic welding it is necessary to protect the weld joint during the plasma tratment to ensure a trouble free welding). |
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[ Application possiblities: ]
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There are many ranges where plasma treatment can be used. But the main applications are: cleaning, activating, etching and coating of surfaces. |
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