JP5123019B2 - High frequency power supply - Google Patents

Description

  The present invention relates to a high-frequency power supply apparatus that supplies high-frequency power to a sputtering apparatus, a chamber apparatus, or the like.

  Conventionally, a high-frequency power supply device that supplies high-frequency power to a load such as a sputtering apparatus or a chamber apparatus is known. The high frequency power supply apparatus performs feedback control so that the high frequency power matches the set power in order to supply preset power (set power) to the load. Specifically, the high frequency power supply device detects high frequency power supplied to the load at the power detection unit, generates new high frequency power so that the high frequency power matches the set power, and loads the generated high frequency power to the load. To supply.

  However, even if the power value of the high-frequency power fed back is not a normal value, the high-frequency power supply device generates new high-frequency power by feedback control and supplies the high-frequency power to the load. For example, when an abnormality occurs in the power detection unit, the high frequency power supply device performs feedback control using a power value of abnormal high frequency power different from the original high frequency power, and thus the newly generated high frequency power is also not normal power. As a result, the load cannot receive the necessary power supply. Further, in the above-described high frequency power supply device, even when an abnormality occurs in a device such as a power detection unit of the feedback control system, the abnormality cannot be detected.

  In order to solve such a problem, for example, a high-frequency power supply device described in Patent Document 1 is known. FIG. 5 is a block diagram showing a configuration of a conventional high-frequency power supply device described in Patent Document 1. In FIG. The high-frequency power supply device 101 includes a setting unit 102, a power output unit 103, a power detection unit 104, a current detection unit 105, a voltage detection unit 106, power calculation units 107 and 108, and an abnormality determination unit 109.

  The setting unit 102 sets a power value (set power Vset) of high-frequency power to be supplied to a load (not shown). The power output unit 103 has a high-frequency power (traveling wave) so that the value of the traveling wave power detection signal Vpf detected by the power detection unit 104 described later becomes a value corresponding to the set power Vset set by the setting unit 102. Electric power) Pf is generated and supplied to a load (not shown).

  The power detection unit 104 detects the traveling wave power Pf output by the power output unit 103 and the reflected wave power Pr returned from the load toward the high frequency power supply device 101. Then, a traveling wave power detection signal Vpf corresponding to the traveling wave power Pf and a reflected wave power detection signal Vpr corresponding to the reflected wave power Pr are generated, and the traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr are used as power. The output is made to the calculation unit 107 and the traveling wave power detection signal Vpf is outputted to the power output unit 103. Traveling wave power detection signal Vpf output to power output unit 103 is used for feedback control.

  Here, the reflected wave power will be briefly described. In general, in order to efficiently supply high-frequency power from the high-frequency power supply device 101 to the load, the impedance on the high-frequency power supply device 101 side and the impedance on the load side must be matched. Such impedance matching is performed by a matching device (not shown) provided therebetween.

  However, since the impedance on the load side fluctuates depending on the operating condition, the impedance matching is not always maintained by the matching device. If the impedance on the load side fluctuates according to the operating condition of the load, the impedance of the high frequency power supply device 101 and the impedance on the load side become mismatched. As a result, part or all of the traveling wave power that is the high frequency power supplied from the high frequency power supply device 101 is reflected by the load, and reflected wave power from the load toward the high frequency power supply device 101 is generated. In this inconsistent state, the high frequency power supply device 101 cannot efficiently supply high frequency power to the load.

  Returning to FIG. 5, the power calculation unit 107 subtracts the reflected wave power detection signal Vpr from the traveling wave power detection signal Vpf output from the power detection unit 104, and outputs the load power P <b> 1 as a subtraction result to the abnormality determination unit 109. To do.

  The current detection unit 105 detects a current in the transmission path between the power output unit 103 and the load, and outputs a current signal Vi corresponding to the current value to the power calculation unit 108. The voltage detection unit 106 detects a voltage in the transmission path between the power output unit 103 and the load, and outputs a voltage signal Vv corresponding to the voltage value to the power calculation unit 108. The power calculation unit 108 performs multiplication and integration calculations on the current signal Vi output from the current detection unit 105 and the voltage signal Vv output from the voltage detection unit 106, and determines the load power P2 as a result of abnormality. Output to the unit 109.

  The abnormality determination unit 109, when the absolute value of the difference between the load power P1 output from the power calculation unit 107 and the load power P2 output from the power calculation unit 108 is equal to or greater than a preset threshold value, It is determined that there is an abnormality and an abnormality signal is output. When the absolute value of the difference between the load power P1 and the load power P2 is not equal to or greater than a preset threshold value, it is determined to be normal.

  As described above, the conventional high-frequency power supply device 101 is based on the traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr when an abnormality occurs in the feedback control system of the power detection unit 104 and the power output unit 103. The abnormality is detected based on the difference between the calculated load power P1 and the load power P2 calculated based on the current signal Vi and the voltage signal Vv in the transmission line.

Japanese Patent Laid-Open No. 2005-77248

  However, the conventional high-frequency power supply device 101 shown in FIG. 5 has a power detection unit 104, a current detection unit 105, a voltage detection unit 106, power calculation units 107 and 108, and an abnormality determination in order to detect an abnormality in the feedback control system. Since the portion 109 is necessary, there is a problem that the overall size is increased, the configuration is complicated, and the cost is increased.

  Therefore, in order to solve the above-described problems, an object of the present invention is to provide feedback with a simple configuration in a high-frequency power supply apparatus that feeds back high-frequency power supplied to a load and performs feedback control so that the high-frequency power matches a set power. An object of the present invention is to provide a high frequency power supply device capable of detecting an abnormality in a control system.

  In order to achieve the above object, a high frequency power supply apparatus according to the present invention is a high frequency power supply apparatus that controls the traveling wave power by a feedback control system so that predetermined set power and traveling wave power supplied to a load coincide with each other. A traveling wave power calculation unit that calculates a traveling wave power detection signal corresponding to the traveling wave power detected by the power detection unit; a traveling wave power calculation unit that detects the traveling wave power; A control unit that generates a control signal by performing feedback control so that the value of the first traveling wave power detection signal calculated by the unit matches the value of the reference signal corresponding to the set power, and generated by the control unit A power converter that converts the generated control signal into traveling wave power to be supplied to the load; and a signal corresponding to the traveling wave power detected by the power detector; An output abnormality detection unit that outputs a second traveling wave power detection signal for detecting an abnormality in the back control system, a first traveling wave power detection signal calculated by the traveling wave power calculation unit, and the output abnormality And a CPU that detects an abnormality of the feedback control system based on the second traveling wave power detection signal output by the detector.

  Further, in the high frequency power supply device according to the present invention, the CPU unit has impedance matching between the high frequency power supply device and the load at the time of adjustment before the load operation, and the set power and traveling wave power Is stored, the second traveling wave power detection signal value output by the output abnormality detection unit in the state of matching, and during load operation, the stored second traveling wave power detection signal value, The value of the second traveling wave power detection signal output by the output abnormality detection unit is compared, and it is determined that an abnormality has occurred in the feedback control system when the two values do not match within a predetermined range. It is characterized by doing.

  Further, in the high frequency power supply device according to the present invention, the CPU section has a value of the first traveling wave power detection signal calculated by the traveling wave power calculation section and a second progression output by the output abnormality detection section. When the value of the wave power detection signal is not in a predetermined relationship, it is determined that an abnormality has occurred in the feedback control system.

  Further, in the high frequency power supply device according to the present invention, the output abnormality detection unit inputs a traveling wave power signal detected by the power detection unit, detects the signal by a diode, amplifies the signal by a differential amplifier, A second traveling wave power detection signal corresponding to the traveling wave power is output.

  As described above, according to the present invention, the traveling wave power detected by the power detection unit is used for feedback control and used to detect an abnormality in the feedback control system. Thereby, since it is not necessary to newly provide a power detection unit for detecting an abnormality in the feedback control system, it is possible to detect the abnormality with a simple configuration.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. In the embodiment of the present invention, the high frequency power supply device that feeds back the high frequency power supplied to the load and performs feedback control so that the high frequency power matches the set power is a traveling wave for feedback control and abnormality detection in the power detection unit. The power Pf is detected, and the abnormality detection traveling wave power detection signal Vpf ′ output by the output abnormality detection unit including a resistor, a diode, a differential amplifier, and the like is compared with the traveling wave power detection signal Vpf for feedback control. If the values of these signals are not in a predetermined relationship, it is determined that an abnormality has occurred in the feedback control system. Further, when the high frequency power supply device is operating normally in the trial operation adjustment before the actual operation, the traveling wave power detection signal Vpf ′ (1) for detecting the abnormality is stored. Then, after the actual operation is started, the stored traveling wave power detection signal Vpf ′ (1) is compared with the traveling wave power detection signal Vpf ′ for abnormality detection output by the output abnormality detection unit, and these If the signal values do not match, it is determined that an abnormality has occurred in the feedback control system.

[Configuration of high-frequency power supply]
First, the configuration of the high frequency power supply device will be described. FIG. 1 is a block diagram showing a configuration of a high frequency power supply device according to an embodiment of the present invention. The high frequency power supply device 1 includes a setting unit 2, a CPU unit 3, a control unit 4, a power conversion unit 5, a high frequency power conversion unit 6, a power detection unit 7, a distribution unit 8, a traveling wave / reflected wave power calculation unit 9, a filter Unit 10 and output abnormality detection unit 11. The high frequency power supply device 1 has a traveling wave so that the traveling wave power detection signal Vpf corresponding to the traveling wave power Pf that is the high frequency power matches the reference signal Vc corresponding to the set power Vset preset by the setting unit 2. The power Pf is feedback controlled and supplied to a load (not shown). Here, a feedback control system is configured by the control unit 4, the power conversion unit 5, the high frequency power conversion unit 6, the power detection unit 7, the distribution unit 8, and the traveling wave / reflected wave power calculation unit 9.

  The setting unit 2 sets the power value (set power Vset) of the high frequency power to be supplied to the load. Here, the set power Vset is, for example, 6 kW or 3 kW. The setting unit 2 corresponds to the setting unit 102 shown in FIG.

  The CPU unit 3 sets the set power Vset set by the setting unit 2, the traveling wave power detection signal Vpf ′ output by the output abnormality detection unit 11, and the traveling wave power output by the traveling wave / reflected wave power calculation unit 9. Each of the detection signal Vpf and the reflected wave power detection signal Vpr is input, and predetermined processing is performed by each means described later to generate a reference signal Vc, an abnormal signal, and a monitor signal. Detailed descriptions of the means included in the output abnormality detection unit 11, the traveling wave / reflected wave power calculation unit 9, and the CPU unit 3 will be described later.

  The control unit 4 receives the reference signal Vc generated by the CPU unit 3 and the traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr output by the traveling wave / reflected wave power calculation unit 9, respectively. Feedback control is performed so that the wave power detection signal Vpf matches the reference signal Vc, and a control signal is generated. In addition, the value of the control signal is limited when the reflected wave power detection signal Vpr is equal to or greater than a preset threshold value. This is to avoid damage to the components of the high frequency power converter 6 due to the traveling wave power Pf converted based on the control signal and the reflected wave power Pr from the load in the high frequency power converter 6. is there. That is, when the value of the reflected wave power detection signal Vpr corresponding to the reflected wave power Pr is large, the value of the control signal generated by the control unit 4 is reduced to suppress the traveling wave power Pf, thereby converting the high frequency power conversion. This is to prevent the parts 6 from being damaged.

  The power conversion unit 5 receives the control signal generated by the control unit 4 and converts the control signal Vcc necessary for outputting the traveling wave power Pf in the high frequency power conversion unit 6. The high frequency power converter 6 receives the control signal Vcc converted by the power converter 5 and converts the control signal Vcc into high frequency power. The high frequency power thus converted is supplied to the load as traveling wave power Pf. Here, the traveling wave power Pf is, for example, high-frequency power of 3.2 MHz or 13.56 MHz when the set power Vset is 6 kW, and high-frequency power of 100 MHz when the set power Vset is 3 Kw. The control unit 4, the power conversion unit 5, and the high frequency power conversion unit 6 correspond to the power output unit 103 illustrated in FIG.

  The power detection unit 7 detects the traveling wave power Pf output from the high frequency power conversion unit 6 and the reflected wave power Pr returned from the load toward the high frequency power supply device 1. The distribution unit 8 receives the traveling wave power Pf detected by the power detection unit 7 and distributes the input traveling wave power Pf to two systems. The traveling wave power Pf distributed by the distribution unit 8 is output to the filter unit 10 and the traveling wave / reflected wave power calculation unit 9. The traveling wave power Pf output to the traveling wave / reflected wave power calculation unit 9 is used as a feedback signal in the feedback control system.

  The traveling wave / reflected wave power calculation unit 9 inputs the traveling wave power Pf distributed by the distribution unit 8 and the reflected wave power Pr detected by the power detection unit 7, respectively, and performs frequency conversion to generate low frequency power. A traveling wave power detection signal Vpf corresponding to the traveling wave power Pf is generated and a reflected wave power detection signal Vpr corresponding to the reflected wave power Pr is generated by performing calculations such as generating and calculating an execution value. . For example, the traveling wave / reflected wave power calculation unit 9 generates a voltage corresponding to the value of the traveling wave power Pf within a range of 0 to 10 V, and outputs a traveling wave power detection signal Vpf of the voltage value. A voltage corresponding to the value of the reflected wave power Pr is generated, and a reflected wave power detection signal Vpr having the voltage value is output. The traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr generated by the traveling wave / reflected wave power calculation unit 9 are output to the CPU unit 3 and the control unit 4. The power detector 7 and the traveling wave / reflected wave power calculator 9 correspond to the power detector 104 shown in FIG. The traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr calculated by the traveling wave / reflected wave power calculator 9 are highly accurate values.

  The filter unit 10 receives the traveling wave power Pf distributed by the distributing unit 8, removes frequency components other than the frequency to be supplied to the load as high frequency power, and outputs the traveling wave power Pf ′.

  The output abnormality detection unit 11 receives the traveling wave power Pf ′ output from the filter unit 10, detects the traveling wave power Pf ′ by a diode, performs signal amplification by a differential amplifier, and travels a power detection signal Vpf ′. Is output. The traveling wave power detection signal Vpf ′ is used for detecting an abnormality in the CPU unit 3. A detailed description of the configuration of the output abnormality detection unit 11 will be described later.

  Here, the traveling wave / reflected wave power calculation unit 9 and the output abnormality detection unit 11 are the same in that they output a traveling wave power detection signal. On the other hand, the traveling wave / reflected wave power calculation unit 9 performs calculation processing such as frequency conversion and effective value calculation, and therefore can output a traveling wave power detection signal Vpf with high accuracy. On the other hand, as will be described later, the output abnormality detection unit 11 is simply configured by a diode, an operational amplifier, a capacitor, a resistor, and the like. Therefore, the traveling wave power detection signal Vpf ′ output by the output abnormality detection unit 11 is different in that it is not as accurate as the traveling wave power detection signal Vpf output by the traveling wave / reflected wave power calculation unit 9. This is because the traveling wave power detection signal Vpf output from the traveling wave / reflected wave power calculation unit 9 is used for feedback control in the control unit 4.

[Configuration of output abnormality detector]
Next, the configuration of the output abnormality detection unit 11 shown in FIG. 1 will be described. FIG. 2 is a circuit diagram showing a configuration of the output abnormality detection unit 11. The output abnormality detector 11 has a function of receiving the traveling wave power Pf ′ and generating and outputting a traveling wave power detection signal Vpf ′ corresponding to the traveling wave power Pf ′. The output abnormality detector 11 includes a differential amplifier circuit composed of an operational amplifier OP and resistors R1 to R4, a power supply V that provides a base voltage for the input signals V1 and V2 to the differential amplifier circuit, and a reference voltage. It comprises resistors R5 and R6 for pressing, diodes D1 and D2, resistors R7 and R8 for compensating the temperature characteristics of these diodes D1 and D2, and capacitors C1 to C3.

  The capacitor C1 and the diode D1 are provided to detect the high frequency of the input traveling wave power Pf ′. The input signal V1 of the differential amplifier circuit is a voltage signal obtained by rectifying the traveling wave power Pf ′ in addition to the reference voltage by the power source V, and the input signal V2 is a signal of the reference voltage by the power source V. Therefore, the difference between the input signal V1 and the input signal V2 is a signal corresponding to the traveling wave power Pf ′, and the traveling wave power detection signal Vpf ′ that is an output signal of the differential amplifier circuit is a signal obtained by amplifying the difference. Thus, the signal corresponds to the traveling wave power Pf ′.

[Configuration of CPU section]
Next, the configuration of the CPU unit 3 shown in FIG. 1 will be described. FIG. 3 is a block diagram illustrating a configuration of the CPU unit 3. The CPU unit 3 includes a set value output unit 31, a monitor output unit 32, an abnormality determination unit 33, and a storage unit 34.

  The set value output means 31 receives the set power Vset set by the setting unit 2, generates a reference signal Vc corresponding to the set power Vset, and outputs the reference signal Vc to the control unit 4. As described above, since the set power Vset is the power value of the high frequency power to be supplied to the load, the set value output means 31 is set to the set power Vset by the control unit 4, the power conversion unit 5, and the high frequency power conversion unit 6. The reference signal Vc is generated so that the corresponding high-frequency power can be generated. For example, the set value output means 31 calculates a voltage value corresponding to the value of the set power Vset within a range of 0 to 10 V, and outputs a reference signal Vc of the voltage value.

  The monitor output means 32 receives the traveling wave power detection signal Vpf and the reflected wave power detection signal Vpr output from the traveling wave / reflected wave power calculation unit 9, and receives the monitoring signal of the traveling wave power Pf and the reflected wave power Pr. Each monitor signal is generated and output as a monitor signal to a display (not shown). Thereby, the user can know the traveling wave power Pf and the reflected wave power Pr from the data displayed on the display.

  The abnormality determination unit 33 includes a traveling wave power detection signal Vpf and a reflected wave power detection signal Vpr output from the traveling wave / reflected wave power calculation unit 9, and a traveling wave power detection signal Vpf ′ output from the output abnormality detection unit 11. , And the reflected wave power detection signal Vpr ′ (1) corresponding to the input reflected wave power detection signal Vpr is read from the storage means 34 described later to determine whether or not an abnormality has occurred in the feedback control system. When it is determined that an abnormality has occurred, an abnormal signal is output to the outside. Thereby, the user can know that an abnormality has occurred in the feedback control system in the high-frequency power supply device 1. In this case, the operation of the load is not performed normally. A detailed description of the processing by the abnormality determination means 33 will be described later.

  In the storage means 34, no abnormality has occurred in the feedback control system in the high-frequency power supply device 1, and when it is operating normally, that is, impedance matching is achieved between the high-frequency power supply device 1 and the load. When the set power Vset and the traveling wave power pf coincide with each other, the traveling wave power detection signal Vpf ′ (1) at that time is stored corresponding to the traveling wave power detection signal Vpf. The normal traveling wave power detection signal Vpf ′ (1) stored in the storage unit 34 is used for processing by the abnormality determination unit 33.

[Abnormality judgment means processing]
Next, processing of the abnormality determination unit 33 in the CPU unit 3 will be described. FIG. 4 is a flowchart showing the processing of the abnormality determination unit 33. First, at the time of trial operation adjustment before actual operation of the load, the abnormality determination unit 33 corresponds to the traveling wave power detection signal Vpf to the traveling wave power detection signal Vpf and the traveling wave power detection signal Vpf ′ when operating normally. The normal traveling wave power detection signal Vpf ′ (1) is stored in the storage means 34 (step S1). Here, normal operation means that no abnormality has occurred in the feedback control system in the high-frequency power supply device 1, the high-frequency power supply device 1 is operating normally, and the impedance on the high-frequency power supply device 1 side. And the load-side impedance are matched, the traveling wave power detection signal Vpf matches the reference signal Vc corresponding to the set power Vset by feedback control (the traveling wave power Pf is set to the set power Vset). In the same state).

  Next, after the actual operation is started, the abnormality determination unit 33 inputs the traveling wave power detection signal Vpf and the traveling wave power detection signal Vpf ′ (step S2), and stores the input traveling wave power detection signal Vpf as a key. The means 34 is searched and the traveling wave power detection signal Vpf ′ (1) corresponding to the traveling wave power detection signal Vpf is read (step S3).

  The abnormality determination unit 33 compares the value of the traveling wave power detection signal Vpf ′ input in step S2 with the value of the traveling wave power detection signal Vpf, and determines whether or not there is a predetermined relationship, for example, Vpf ′ = √Vpf. It is determined whether or not there is (step S4). Specifically, whether or not the value of traveling wave power detection signal Vpf ′ is within a predetermined upper and lower threshold range with respect to a value obtained by route calculation of the value of traveling wave power detection signal Vpf. Determine.

  When the abnormality determination means 33 determines that Vpf ′ = √Vpf (step S4: Y), the value of the traveling wave power detection signal Vpf ′ input in step S2 and the traveling wave power detection signal read in step S3 The value of Vpf ′ (1) is compared, and it is determined whether or not they match, that is, whether or not Vpf ′ = Vpf ′ (1) (step S5). Specifically, it is determined whether the value of traveling wave power detection signal Vpf ′ is within the preset upper and lower thresholds with respect to the value of traveling wave power detection signal Vpf ′ (1). judge.

  When it is determined that Vpf ′ = Vpf ′ (1) (step S4: Y), the abnormality determination unit 33 determines that no abnormality has occurred in the feedback control system and is normal (step S6).

  On the other hand, when it is determined in step S4 that Vpf ′ = √Vpf is not satisfied (step S4: N), the abnormality determination unit 33 determines that an abnormality has occurred in the feedback control system and outputs an abnormality signal (step S4). S7). For example, when an abnormality occurs in the traveling wave / reflected wave power calculation unit 9 in the feedback control system, the traveling wave power detection signal Vpf output by the traveling wave / reflected wave power calculation unit 9 becomes an abnormal value. In this case, Vpf ′ ≠ √Vpf, and the abnormality determination unit 33 determines the occurrence of abnormality.

  Further, when it is determined in step S5 that Vpf ′ = Vpf ′ (1) is not satisfied (step S5: N), the abnormality determination means 33 determines that an abnormality has occurred in the feedback control system and outputs an abnormality signal. (Step S7). For example, when an abnormality occurs in the power detection unit 7 in the feedback control system, the traveling wave power detection signal Vpf ′ output from the output abnormality detection unit 11 becomes an abnormal value. In this case, Vpf ′ ≠ Vpf ′ (1), and the abnormality determination unit 33 determines the occurrence of abnormality.

  And the abnormality determination means 33 will complete | finish a process, if a driving | operation complete | finishes (step S8: Y), and on the other hand, as long as a driving | running continues, the process of step S2-step S7 is continued (step S8: N). The abnormality determination means 33 does not execute the reading process of the traveling wave power detection signal Vpf ′ (1) in step S3 unless the value of the traveling wave power detection signal Vpf input in step S2 is changed, and proceeds. If there is a change in the value of the wave power detection signal Vpf, it may be executed.

  As described above, according to the high frequency power supply device 1 according to the embodiment of the present invention, the CPU unit 3 detects the traveling wave power for detecting an abnormality output by the output abnormality detecting unit 11 of a system different from the feedback control system. When the signal Vpf ′ and the traveling wave power detection signal Vpf for feedback control output by the traveling wave / reflected wave power calculation unit 9 are not in a predetermined relationship, it is determined that an abnormality has occurred in the feedback control system. I tried to do it. Further, the CPU unit 3 stores the traveling wave power detection signal Vpf ′ (1) at the normal time output from the output abnormality detecting unit 11, and the traveling wave power detection signal Vpf for detecting the abnormality at the normal time. If (1) and the traveling wave power detection signal Vpf for abnormality detection output by the output abnormality detection unit 11 do not match, it is determined that an abnormality has occurred in the feedback control system. did. Thereby, an abnormality of the feedback control system can be detected.

  Moreover, according to the high frequency power supply device 1 according to the embodiment of the present invention, the traveling wave power Pf is detected by one power detection unit 7, and the traveling wave power Pf is shared to control the feedback control system and the feedback control. System anomaly detection was performed. Thereby, since it is not necessary to provide a new electric power detection part, abnormality of a feedback control system can be detected with a simple configuration. Further, since the number of additional parts can be reduced, the overall size can be reduced, and the cost can be minimized.

  Further, according to the high frequency power supply device 1 according to the embodiment of the present invention, the output abnormality detection unit 11 is simply configured as shown in FIG. 4, so the high frequency power supply device 1 is the conventional one shown in FIG. 5. Compared with the high frequency power supply apparatus 101, the abnormality of the feedback control system can be detected with a simple configuration as a whole.

  Further, according to the high frequency power supply device 1 according to the embodiment of the present invention, the traveling wave / reflected wave power calculation unit 9 performs calculation processing such as frequency conversion and effective value calculation on the input traveling wave power Pf, and proceeds. The wave power detection signal Vpf is output. As a result, the traveling wave power detection signal Vpf can be a highly stable signal in the feedback control system in addition to being a highly accurate signal. Further, since the CPU unit 3 detects an abnormality of the feedback control system using the highly accurate and stable traveling wave power detection signal Vpf output from the traveling wave / reflected wave power calculation unit 9, the abnormality detection is performed. It can be realized with high accuracy.

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical idea thereof. In the embodiment, the output abnormality detection unit 11 is configured by a diode, an operational amplifier, a resistor, and the like. However, the present invention is not limited to this, and a traveling wave power detection signal corresponding to the traveling wave power Pf ′ is used. It suffices if Vpf ′ can be generated and output.

It is a block diagram which shows the structure of the high frequency power supply device by embodiment of this invention. It is a circuit diagram which shows the structure of an output abnormality detection part. It is a block diagram which shows the structure of CPU part. It is a flowchart which shows the process of the abnormality determination means of CPU part. It is a block diagram which shows the structure of the conventional high frequency power supply device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 High frequency power supply device 2,102 Setting unit 3 CPU unit 4 Control unit 5 Power conversion unit 6 High frequency power conversion unit 7, 104 Power detection unit 8 Distribution unit 9 Traveling wave / reflected wave power calculation unit 10 Filter unit 11 Abnormal output Detection unit 31 Set value output unit 32 Monitor output unit 33 Abnormality determination unit 34 Storage unit 103 Power output unit 105 Current detection unit 106 Voltage detection unit 107, 108 Power calculation unit 109 Abnormality determination unit

Claims (4)

In the high frequency power supply device that controls the traveling wave power by a feedback control system so that the predetermined set power matches the traveling wave power supplied to the load,
A power detector for detecting the traveling wave power;
A traveling wave power calculation unit that calculates a first traveling wave power detection signal corresponding to the traveling wave power detected by the power detection unit;
A control unit that performs feedback control so that the value of the first traveling wave power detection signal calculated by the traveling wave power calculation unit matches the value of the reference signal corresponding to the set power, and generates a control signal;
A power conversion unit that converts the control signal generated by the control unit into traveling wave power to be supplied to a load;
An output abnormality detection unit that detects a signal corresponding to the traveling wave power detected by the power detection unit and outputs the signal as a second traveling wave power detection signal for detecting an abnormality of the feedback control system;
An abnormality in the feedback control system is detected based on the first traveling wave power detection signal calculated by the traveling wave power calculation unit and the second traveling wave power detection signal output by the output abnormality detection unit CPU section to
A high frequency power supply device comprising: The high frequency power supply device according to claim 1,
When the CPU section adjusts before the load operation, the output abnormality in a state in which impedance matching is achieved between the high frequency power supply device and the load, and the set power and traveling wave power match. Storing the value of the second traveling wave power detection signal output by the detector;
During the load operation, the stored value of the second traveling wave power detection signal is compared with the value of the second traveling wave power detection signal output by the output abnormality detection unit, and both values are within a predetermined range. A high-frequency power supply apparatus that determines that an abnormality has occurred in the feedback control system when they do not match. The high frequency power supply device according to claim 1 or 2,
The CPU unit has a predetermined value of the first traveling wave power detection signal calculated by the traveling wave power calculation unit and a value of the second traveling wave power detection signal output by the output abnormality detection unit. A high-frequency power supply apparatus that determines that an abnormality has occurred in the feedback control system when there is no relationship. In the high frequency power supply device according to any one of claims 1 to 3,
The output abnormality detection unit receives a traveling wave power signal detected by the power detection unit, detects the signal by a diode, amplifies the signal by a differential amplifier, and outputs a second traveling wave corresponding to the traveling wave power. A high frequency power supply device that outputs a wave power detection signal.

Images