Patent · US Expired

Discharge method and apparatus for generating plasmas

US6059935A · kind A · utility

50Cited by
107References
44Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 22, 1998
Grant dateMay 9, 2000
Priority date
Expiry dateDec 22, 2018

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S422/906
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Two methods and corresponding electrode designs are provided for the generation of a plasma, for example, at or about one atmosphere. Using these methods, various webs, films and three-dimensional objects are beneficially treated in a reduced amount of time. A first method utilizes a repetitive, asymmetric voltage pulse to generate a plasma discharge between two electrodes. An asymmetric voltage pulse is used to generate a discharge in which a substrate can be exposed predominately to either positive or negative plasma species depending on the voltage polarity used. A second method uses the gap capacitance of an electrode pair and an external inductor in shunt to form a resonant LC circuit. The circuit is driven by a high power radio frequency source operating at 1 to 30 MHz to generate a uniform discharge between the electrode pair. Both methods have temperature controlled discharge surfaces with supply gas temperature, humidity and flow rate control. The gas flow is typically sufficient to cause a turbulent flow field in the discharge region where materials are treated. Electrode pairs implement these methods and include a metal faced electrode and a dielectric covered electrode,…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.