Wetzlar  /  25.9.2018  -  26.9.2018

8. Wetzlarer Herbsttagung »Moderne Optikfertigung«

Dass Atmosphärendruckplasmen als eine vielversprechende Alternative zu den für die Behandlung optischer Oberflächen weit verbreiteten Niederdruck-Plasmaverfahren in Betracht gezogen werden können, bespricht Stephan Brückner vom Anwendungszentrum für Plasma und Photonik des Fraunhofer IST anhand seiner erzielten Forschungsergebnisse in seinem Vortrag auf der Wetzlarer Herbsttagung. Diese findet in diesem Jahr bereits zum 8. Mal statt.

»Atmospheric pressure plasma as inline-capable surface treatment in preparation for cementing and adhesive processes«

Stephan Brückner, Marko Eichler

For the treatment of optical surfaces, low-pressure plasma techniques are widely available and provide a well-established means for fine cleaning and activating various materials. However, atmospheric-pressure plasmas are considered as a promising alternative, when vacuum processes are not compelling and when highly flexible, in-line capable processes offer advantages for the production chain. In this contribution, we present a technique for the finishing of precision optical components, based on an atmospheric-pressure plasma. Amongst a fine cleaning and surface smoothing, the goal is to enhance the performance of adhesives and cements, as well as to improve the long term stability of cemented and coated optical components.

The used plasma source is based on the principle of a dielectric barrier discharge (DBD) and generates a »cold« plasma at ambient temperature (gas temperature approx. 30-90°C). The plasma source was implemented in a cleanroom workstation and tested in a practical manufacturing environment. During the plasma treatment, a distinct decrease of carbon-containing contaminations attached to the surface can be detected. Associated with that, a significant influence of the plasma on the wettability of the treated surfaces, and thus, a significant increase of the adhesive strength can be observed. This project was funded by the Federal Ministry for Economics Affairs and Energy in the program ZIM (ZF4157701DF5; ZF4047502DF5).