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Verfahren zur Steuerung einer Vakuum-Lichtbogenentladung

Method for metal-coating by arc-discharge in vacuum - applies laser pulses to voltage surface at max. voltage across anode and cathode
 
: Schulze, D.; Wilberg, R.; Fleischer, W.; Pompe, W.; Scheibe, H.J.; Siemroth, P.; Steigmann, E.

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Frontpage ()

DD 1988-313264 A: 19880301
DE 1989-3901401 A: 19890119
DE 3901401 C2: 19961219
H05H0001
German
Patent, Electronic Publication
Fraunhofer IWS ()

Abstract
The invention relates to a process for the control of a vacuum arc such as used in the form of a so-called cold-cathode arc vaporizer for the vaporization of conductive materials, in particular of metals for a wide variety of applications, e.g. for the purposes of reactive plasma-assisted hard material coatings. The invention is based on the task of finding a process which minimizes the droplet formation on the cathode by the reliable control of the arc spot movement and increases cathode material utilization. According to the invention, the task is solved by the fact that the voltage between the anode and the cathode is applied in pulses and a laser pulse defined locally at maximum voltage is directed at the cathode surface.

 

DE 3901401 A UPAB: 19971006 The method applies the voltage between anode and cathode in pulses. At max. voltage a laser pulse defined locally is directed at the cathode surface. The max. voltage between anode and cathode lies below the voltage for automatic ignition of an arc discharge. The min. voltage between anode and cathode lies below the min. ignition voltage of the arc discharge. The sequence of impact locations of the laser pulse is guided uniformly or according to a given pattern over the cathode surface. The pulse length is chosen so that the max. expected shift in cathode focus during a pulse in smaller than the smallest distance to the edge of the target. Layer thickness is set by the number of pulses. USE/ADVANTAGE - For making multiple-layers by arc discharge. Minimises droplet formation.

: http://publica.fraunhofer.de/documents/PX-39532.html