A plasma processing apparatus includes a plasma generating device configured to generate a plasma within a processing vessel by using a high frequency wave generated by a microwave generator 41 including a magnetron 42 configured to generate the high frequency wave; detectors 54 a and 54 b configured to measure a power of a traveling wave that propagates to a load side and a power of a reflected wave reflected from the load side, respectively; and a voltage control circuit 53 a configured to control a voltage supplied to the magnetron 42 by a power supply 43 . Further, the voltage control circuit 53 a includes a load control device configured to supply, to the magnetron 42 , a voltage corresponding to a power calculated by adding a power calculated based on the power of the reflected wave measured by the detector 54 b to the power of the traveling wave measured by the detector 54 a.

Plasma processing apparatus, plasma processing method and high frequency generator

The electrical power supply to a magnetron (M) is regulated as a function of an instantaneous microwave power setpoint by: predetermining and storing (20) a value (η) for the electrical efficiency of the magnetron; inputting (19) a setpoint mean microwave power value, and converting it into a low frequency setpoint instantaneous power signal that is sampled at high frequency; measuring (8, 9) and sampling the instantaneous values of anode current and of the high voltage fed to the magnetron; calculating (10) the difference at a sampling instant (n) between the setpoint instantaneous microwave power and the product of the current multiplied by the high voltage multiplied by the efficiency; determining an instantaneous microwave power value at the consecutive sampling instant (n+1) that is corrected as a function of a predetermined regulation relationship that is valid at said instant (n+1); and converting it into an analog signal representative of the corrected instantaneous microwave power for powering the magnetron.

Method and a device for regulating the electrical power supply to a magnetron, and an installation for treating thermoplastic containers being an application thereof

PROBLEM TO BE SOLVED: To provide a plasma processing device which enables the rise in the detection accuracy of travelling wave power and the detection accuracy of reflected wave power.SOLUTION: In a plasma processing device 1, a first directional coupler 80 is provided on a first wave guide 21 connecting a microwave generation part 16 to a first port 25a of a circulator 25. A first detector 82 is connected to the first directional coupler 80. A second port 25b of the circulator 25 is connected to a plasma generation part through a second wave guide 22. A second directional coupler 84 is provided on a third wave guide 23 connecting a third port 25c of the circulator 25 to a dummy load 24. To the second directional coupler 84, a second detector 86 is connected.SELECTED DRAWING: Figure 1

Plasma processing device

PROBLEM TO BE SOLVED: To improve and optimize the accuracy of the instantaneous microwave power emitted by the magnetron compared with the instantaneous setpoint power in a context. SOLUTION: The electrical power supply to a magnetron is regulated as a function of an instantaneous microwave power setpoint by: predetermining and storing a value (eta) for the electrical efficiency of the magnetron; inputting a setpoint mean microwave power value, and converting it to obtain a setpoint of the instantaneous values of a power signal; measuring and sampling the instantaneous values of anode current and of the high voltage fed to the magnetron; calculating the product of the instantaneous value of the anode current multiplied by the instantaneous value of the high voltage at the sampling instant, and multiplied by the previously determined value for the electrical efficiency of the magnetron, in order to obtain the instantaneous microwave power value as measured at the sampling instant; determining an instantaneous microwave power value at the consecutive sampling instant that is corrected as a function of a predetermined regulation relationship that is valid at the instant; and converting it into an analog signal representative of the corrected instantaneous microwave power. COPYRIGHT: (C)2008,JPO&INPIT

Method and device for regulating electrical power supply to magnetron

PROBLEM TO BE SOLVED: To provide a microwave power supply system and a travelling-wave power control method of the microwave power supply system by propagating a load-side supply power of a given value further toward the load side than an input end 3a of a manual matching unit 3, by keeping the load-side supply power value PL at a given value through an incremental compensation of a travelling-wave power value PF by the value by which a reflective wave power value PR is increased and the load-side supply power value PL is decreased, without augmenting a processing time and without augmenting an adjustment man-hour SOLUTION: With the microwave power supply system and its travelling-wave power control method, an output power setting signal Vst and a reflective wave power value signal Vpr corresponding in size to the reflective wave power value PR are added without changing the movable position of the impedance element from an initial operation state even at processing after the initial operation state of the system, and a magnetron supply power PM making an anode current Ia of the magnetron change in accordance with the above added signals is supplied to the magnetron to output the travelling wave power PF from the output end of a microwave power source 1 COPYRIGHT: (C)2004,JPO

Hosokawa Atsushi

Papers

Microwave power supply system and travelling-wave power control method of microwave power supply system