Jörn Leiber

New design of a plasma chamber for homogeneous web treatment

Abstract This paper describes a plasma treatment and coating system which is used to modify polymer web films with a width of up to 0.5 m. The main focus of the description is a new design of the plasma chamber geometry, gas distribution (inlet and outlet) and electrodes assembly. An electrode mounting support has been constructed which enables a quick exchange of the powered electrode (cathode). This permits a marked extension of the real operating time of the system. A second feature is the design of the gas and precursor feeding tube, which results in a homogeneous gas supply along the substrate width. This uniform gas flow is supported by a corresponding design of the exhaust opening. The uniformity of the plasma process is investigated in an exemplary manner by treatment of polyester films with a CF 4 plasma and surface characterization by contact angle measurements and electron spectroscopy for chemical analysis. The measurements showed a good homogeneity of the treatment along the width of the polymer film.