Papers

ICMCTF2002 Session G5-1: Large Area Production Coatings; Plasma Cleaning and Pretreatment of Large Surfaces

Monday, April 22, 2002 10:30 AM in Room Sunrise

Monday Morning

Start	Invited?	Item
10:30 AM		G5-1-1 Thermal Load During High-rate Deposition onto Large Areas by Electron Beam Evaporation J.-P. Heinss, Chr. Metzner (Fraunhofer FEP, Germany) High-rate electron beam evaporation is the most powerful PVD technology, especially for the coating of large areas e.g. metal strips and plastic foils. One of the main limitations of this technology is the thermal load of the substrate during deposition. The electron beam evaporation is accompanied by several effects that are responsible for substrate heating. In many cases upper temperature limits for the substrate or the layer material exist. That's why the application of the electron beam evaporation, especially for very thin substrates, is often limited. An overview about the quantitative relations of the energy fluxes and the general possibilities for reducing the heating up of the substrate during high-rate electron beam evaporation is given. The thermal load of flat substrates during the deposition is calculated. In this calculation a term of a substrate cooling is taken into consideration. We demonstrate the influence of a cooling process and deduce necessary values of it. The discussion of the principal methods of substrate cooling during a vacuum process assesses the chances for a realisation in a deposition equipment. The results of first investigations concerning a cooling equipment for flat metal substrates will be presented.
10:50 AM		G5-1-2 Dual-anode Magnetron Sputtering. A. Belkind, Z. Zhao (Stevens Institute of Technology); R. Scholl (Advanced Energy Industries, Inc.) Reactive sputtering of dielectrics suffers from an anode problem, which appears when the anode becomes coated with a dielectric layer. A solution to the anode problem is a self-cleaning anode system. It can consist of two anodes and a single magnetron driven by a mid-frequency AC power supply via a center-taped isolation transformer. The anodes are connected to the ends of the secondary coil of the transformer, while the magnetron to its center tap. Such a novel configuration is called Dual-anode Reactive Magnetron Sputtering system, and has been developed in this work. This configuration creates a self-cleaning regime for both anodes, and provides dynamically cleaned and sustainable anodes. To provide biasing, the substrate holder is connected to the magnetron through a resistor and/or additional floating power supply. Introducing dual anodes does not restrict implementation of closed-loop control for high rate deposition of transparent and scratch-resistant Al₂O₃ films. High-rate deposition of dielectrics, using biased dual-anode reactive sputtering, is proved to be a reliable technology for making dense Al₂O₃ and other films.
11:10 AM		G5-1-3 Innovative Steel Strip Coatings by Means of PVD in a Continuous Pilot Line: Process Technology and Coating Development B. Schuhmacher, C. Schwerdt (DOC Dortmunder Oberflächencentrum GmbH - a company of ThyssenKrupp Steel, Germany); U. Seyfert (von Ardenne Anlagentechnik GmbH, Germany); O. Zimmer (Fraunhofer-Institut Werkstoff- und Strahltechnik, Germany) Steel producers today are faced to increasing demands of end users on steel sheet with respect to significantly enhanced corrosion protection and increasingly complex surface functional properties as well. Since it becomes more and more obvious that these requirements cannot be achieved using only the available conventional continuous steel strip coating processes such as hot-dip or electro-galvanising, alternative coating processes such as PVD have to be considered. Based on PVD coating of already conventionally zinc coated steel strip novel approaches to highly corrosion resistant zinc alloy coatings have been developed on a laboratory scale. In this paper, the successful up-scaling of such an approach to a continuous pilot line with line speed up to 60 m/min and strip width of 300 mm is reported. The PVD technology of the pilot line comprises different plasma cleaning processes, thermal evaporation by means of radiation heating as well as electron beam evaporation. In-line layer thickness measuring will be performed by means of XRF-techniques. First results of coating development by means of evaporating thin additional layers of different metals on already conventionally zinc coated steel strip will be presented.
11:50 AM		G5-1-5 Study of Pretreatment Methods for Vacuum Metallization of Plastics K. De Bruyn, M. Van Stappen (WTCM Surface Treatment, Belgium); H. De Deurwaerder, L. Rouxhet (CRIF, Belgium); J.P. Celis (Catholic University of Louvain, Belgium) In this study some aspects of the vacuum metallization of plastics and composite materials were investigated from an industrial point of view. The study involved the most commonly used substrate materials being ABS, PC, PP and a composite (glass fiber/epoxy resin) material. Substrates were subjected to industrially feasible pretreatments such as flame treatment, chemical treatment, mechanical treatment, oxygen plasma and also a lacquer treatment. Surface characterization before and after the pretreatments has been done by atomic force microscopy, X-ray photo-electron spectroscopy and contact angle measurements. An aluminium layer was deposited by magnetron sputtering to nominal thicknesses of 0.1 and 1.0 µm. The adhesion of the metallic layer was studied by the cross-cut test (ISO 2409) and the falling-weight test (ISO 6272), two standardized methods that can be easily performed in an industrial environment. The results indicate that these tests can only be used for a go or no-go decision on the adhesion.