The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 29, 2011
Filed:
Sep. 28, 2007
Ryohei Tanaka, Osaka, JP;
Ryohei Tanaka, Osaka, JP;
DAIHEN Corporation, Osaka, JP;
Abstract
An arc detector is provided for a plasma processing system including a HF power source, a plasma processor, and a voltage/current signal detector. The arc detector includes a calculator for the phase difference between the AC voltage signal and the AC current signal, a calculator for an effective voltage based on the AC voltage signal, a calculator for an effective current based on the AC current signal, an FFT processor for the frequency spectrum of the AC voltage or current signal, and an arc analyzer connected to the phase difference calculator, effective voltage calculator, effective current calculator, and FFT processor. The arc analyzer calculates the plasma processor's impedance based on the calculated phase difference, effective voltage, and effective current. The arc analyzer monitors arcs in the plasma processor, based on the fluctuation rate of the calculated impedance and the output level of a frequency component in the spectrum.