IP Library Granted Patent US 9,756,713
Granted Patent B2
US 9,756,713 · App. 14/648,426 · Granted Sep 5, 2017

Method and control unit for operating a plasma generation apparatus

Inventors: Florian Liechti (Meisterschwanden, CH); Albert Friedery (Berlingen, CH); Hartmut Koschnitzke (Winterthur, CH); Rene Groeber (Dintikon, CH)
Assignee: OERLIKEN METCO AG, WOHLEN
H05H1/30H05H1/0081H05H1/36
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Quick Facts
Patent No.
US 9,756,713
App. No.
14/648,426
Granted
Sep 5, 2017
Kind
B2
Abstract

The invention relates to a method and to a control unit for operating the plasma generation apparatus. The invention is based on a method and a control unit in which a voltage is applied as an ignition voltage between an anode and a cathode for ignition of a plasma. In order to enable a gentle operation of the plasma generation apparatus it is provided in accordance with the invention that a check is continuously carried out during the ignition process whether the ignition of the plasma has been effected. Additionally, the ignition voltage (U Z ) is increased starting from an initial ignition voltage (U ZA ) and after recognizing an effected ignition (at the point in time t Z ) of the plasma, the voltage is reduced between the anode and the cathode to a maintenance voltage (U A ).

Claims (43)

1. A method of initiating plasma in an apparatus comprising an anode and a cathode, the method comprising:

applying a maintenance voltage between an anode and a cathode;

applying an igniting voltage between the anode and the cathode in order to cause ignition of plasma;

increasing the igniting voltage;

continuously checking to determine whether the ignition of the plasma has occurred; and

when ignition of the plasma is determined to have occurred, reducing or stopping the igniting voltage so that the voltage between the anode and the cathode is reduced to the maintenance voltage.

2. The method of claim 1 , wherein the igniting voltage increases from a start igniting voltage.

3. The method of claim 2 , wherein the start igniting voltage is zero volts.

4. The method of claim 1 , wherein the continuously checking comprises measuring a current flow between the anode and the cathode.

5. The method of claim 1 , wherein the igniting voltage increases monotonically from a start igniting voltage.

6. The method of claim 1 , wherein the ignition voltage increases at a constant rate from a start igniting voltage.

7. The method of claim 1 , wherein the applying the igniting voltage comprises applying an increasing igniting voltage via an ignition device.

8. The method of claim 7 , wherein, when ignition of the plasma is determined to have occurred, the ignition device is disconnected from the anode and/or the cathode.

9. The method of claim 1 , further comprising identifying the anode and the cathode prior to the ignition of the plasma.

10. The method of claim 1 , further comprising reading an identification parameter associated with the anode and the cathode prior to the ignition of the plasma.

11. The method of claim 1 , further comprising detecting and storing at least one parameter of the anode and the cathode.

12. The method of claim 1 , further comprising detecting and storing the igniting voltage associated with the cathode and the anode.

13. The method of claim 1 , further comprising at least one of:

storing and evaluating an end igniting voltage that is reached upon the ignition of the plasma; and

detecting an end igniting voltage that is reached upon the ignition of the plasma.

14. The method of claim 1 , further comprising:

prior to the ignition of the plasma, comparing a stored parameter associated with the anode and the cathode.

15. The method of claim 1 , further comprising:

comparing a stored parameter associated with the anode and the cathode; and

controlling the maintenance voltage and/or the igniting voltage.

16. The method of claim 1 , further comprising:

identifying the anode and the cathode;

comparing a stored parameter associated with the anode and the cathode; and

controlling the maintenance voltage and/or the igniting voltage.

17. A plasma initiation control system comprising:

a maintenance voltage source connected to and supplying to a maintenance voltage to an anode and a cathode of a plasma generating apparatus;

an ignition voltage source connected to and supplying an igniting voltage to the anode and the cathode;

a control unit structured and arranged to continuously check to determine whether ignition of a plasma has occurred, increase the igniting voltage starting from an initial ignition voltage, and detect the ignition of the plasma and stop or reduce the igniting voltage.

18. The plasma initiation control system of claim 17 , wherein the maintenance voltage source and an ignition voltage source are separate voltage sources.

19. A plasma initiation control system comprising:

a voltage source connected to an anode and a cathode of a plasma generating apparatus;

an ignition voltage source connected to the anode and the cathode;

a control unit connected to the ignition voltage source and being structured and arranged to each of: continuously check to determine whether ignition of a plasma has occurred, and control the ignition voltage source such that upon detecting the ignition of the plasma, an igniting voltage supplied by the ignition voltage source is reduced or stopped.

20. A method of initiating plasma using a plasma initiation control system comprising a voltage source connected to an anode and a cathode of a plasma generating apparatus, an ignition voltage source connected to the anode and the cathode, and a control unit connected to the ignition voltage source, the method comprising:

maintaining a voltage between an anode and a cathode;

during the maintaining, applying an increasing igniting voltage between the anode and the cathode;

during the applying, continuously checking to determine whether the ignition of the plasma has occurred; and

when ignition of the plasma is determined to have occurred, reducing the igniting voltage while maintaining the voltage.

Assignments (2)
CHANGE OF NAME Recorded Sep 23, 2016
From: OERLIKON METCO AG
To: OERLIKON METCO AG, WOHLEN
Reel/Frame 040135/0083 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 28, 2016
From: LIECHTI, FLORIAN; FRIEDERY, ALBERT; KOSCHNITZKE, HARTMUT; GROEBER, RENE
To: OERLIKON METCO AG
Reel/Frame 038113/0015 →
Priority Claims (1)
EP 12195367 · Dec 4, 2012 · regional
Continuity (1)
Related Publication 20150319834A1 · Nov 5, 2015