Conventional plasma source concepts offer numerous possibilities for the full or selective activation or functionalization of surfaces. Complicated 3D geometries such as deep grooves, cavities, or undercuts on the other hand often can only be treated incompletely. Achieving the homogeneous treatment of the entire surface on all sides requires discharges that are, as far as possible, loss-free and true to the contour.
The new plasma source
A possible solution is offered by the plasma source concept developed at Fraunhofer IST based on a dielectric impeded surface discharge.
What is known as a "cold" surface discharge in the range of 30 to 60° C permits laminar and contoured as well as depth processing, even of temperature-sensitive substrates.
A concentric plasma gas supply creates a homogeneous surface discharge that generates discharge widths between 20 and 80 mm depending on distance of the source to the substrate (1 mm to 30 mm). Diverse homogeneous functionalization of the substrate surface is also possible regardless of the substrate thickness and conductivity by choosing the process gas such as compressed air, argon, helium, or nitrogen
The surface discharges that are produced can be realized on a wide variety of materials such as glass, plastics, metals, or wood. Possible uses include the adhesion-optimized application of coatings or adhesives in the polymer processing industry and the ultra-fine cleaning of metals.