JP4391465B2 - AC power supply apparatus and arc suppression method in the apparatus - Google Patents

Description

  The present invention relates to an AC power supply device, and in particular, in a manufacturing apparatus field for manufacturing a semiconductor, a liquid crystal substrate, or the like using a process such as sputtering, an arc generated during the process is suppressed and the generated arc energy is reduced. The present invention relates to an AC power supply apparatus suitable for minimization and an arc suppression method in the apparatus.

  Generally, in a sputtering apparatus, a sputtering process is realized by causing plasma discharge in a manufacturing apparatus. In order to realize this process, it is necessary to apply high voltage direct current (DC) power supply or alternating current (AC) power supply to the electrodes in the manufacturing apparatus, thereby causing plasma discharge.

  However, when this high-voltage power source is applied between the electrodes where the plasma is floating, breakdown voltage occurs between the electrodes, a short circuit phenomenon occurs, and an excessive current may flow. This short-circuit phenomenon is a so-called arc phenomenon. When this arc is generated, there is a problem that foreign matter is scattered in the product and the commercial value is impaired. For this reason, it has become indispensable to suppress the influence on the product by capturing the arc phenomenon and cutting off the power supply at high speed. Conventionally, a DC power supply has been used in many cases, but an AC power supply is also used. As a method of capturing this arc phenomenon, a method of intercepting power supply by capturing a change in the supplied direct current or alternating current is generally used. It is used.

  Moreover, there exists a thing of patent document 1 as an apparatus which catches an arc phenomenon and interrupts at high speed. As shown in FIG. 8, the device converts the DC voltage obtained by the DC control unit 1 and taken out through the smoothing circuit 2 into AC (rectangular wave) by the inverter switching unit 3, The rectifier 5, the discharge voltage detection circuit 6, and the current transformer 7 are supplied to the processing apparatus main body 12. A discharge voltage detection signal obtained from the discharge voltage detection circuit 6 disposed between the rectifier 5 and the processing apparatus main body 12 is sent to a discharge voltage fall detection circuit 8 including a differentiation circuit. The discharge voltage fall detection circuit 8 is supplied with an inverter control signal from the inverter control unit 11. The inverter control unit 11 outputs an inverter control signal to the gate drive 10 based on the arc detection signal obtained as the output of the discharge voltage fall detection circuit 8, stops the operation of the inverter switching unit 3, and sends it to the processing apparatus main body 12. Shut off the power supply.

JP-A-7-233472

  As described above, conventionally, a method of intercepting power supply by capturing a change in supplied DC current or AC current has been adopted. For this reason, there is a problem that a period from when the arc is detected to when the power supply is cut off is long, and in particular, there is a possibility that a problem that the time until the arc is detected is long. In Patent Document 1, the discharge voltage fall detection circuit 8 determines arc detection by a differentiation circuit based on the discharge voltage, and outputs an arc detection signal. And the inverter control part 11 stops the operation | movement of the inverter switching part 3 based on the said arc detection signal, and interrupts | blocks the electric power feeding to the processing apparatus main body 12. FIG. For this reason, there is a possibility that the quality of the arc detection signal deteriorates due to a delay caused by signal processing of the differentiation circuit in the discharge voltage rising detection circuit 8 or switching noise of the inverter.

  Therefore, the present invention suppresses arcs generated during the process and minimizes the generated arc energy in the field of manufacturing equipment that manufactures semiconductors, liquid crystal substrates, etc. using processes such as high-frequency power supply devices, especially sputtering. It is an object of the present invention to provide an AC type power supply apparatus suitable for suppression and an arc suppression method in the apparatus.

In order to achieve the above object, the present invention provides a power source for supplying high-frequency AC power converted from commercial AC power to electrodes in a load device, wherein the AC power source device suppresses an arc generated between the electrodes . An AC-DC rectifier that generates DC power from the commercial AC power, a DC-DC power converter that converts the DC power into DC power suitable for a load, and a high frequency that converts the converted DC power into high-frequency AC power A power converter; a high-frequency transformer that insulates the high-frequency AC power from a commercial AC power supply; current change rate suppression means that suppresses a change rate of current obtained from the isolated high-frequency AC power; and the insulated high-frequency AC A voltage detector for detecting an output voltage of the power to the load device, a pulse command waveform for driving a power element of the high-frequency power converter, and the output power And arc suppression means for detecting the occurrence of an arc when both waveforms are different from each other, blocking the supply of high-frequency AC power to the load device, and suppressing arc energy. .

  Preferably, the current change rate suppression means is a reactor. Preferably, the voltage detector detects an output voltage of a reactor provided between a high-frequency transformer and a load device, and the arc suppression means detects high-frequency power when the occurrence of the arc is detected. The power element gate of the converter is turned off. Further preferably, the arc suppression means compares the level values of the pulse command waveform and the waveform of the output voltage, and detects the occurrence of an arc when the two level values are different.

Further, the present invention provides a method of suppressing an arc more high-frequency AC power converted from a commercial AC power to the AC power supply supplied to the electrodes in the load device, generated between the electrodes, a direct current from the commercial AC power power An AC-DC rectification step for generating DC power, a DC-DC power conversion step for converting the DC power into DC power suitable for a load, a high-frequency power conversion step for converting the converted DC power into high-frequency AC power, and To a power insulation process for insulating high-frequency AC power from the AC power source, a current rate-of-change suppression process for suppressing a rate of change of current obtained from the insulated high-frequency AC power, and a load device in the insulated high-frequency AC power A voltage detection step for detecting the output voltage of the output, a pulse command waveform for driving a power element used in the high-frequency power conversion step, and a waveform of the output voltage Comparing, detecting the occurrence of an arc when the two waveforms are different, to cut off the supply to the high-frequency AC power of the load device, characterized in that it comprises a suppressing arc suppression process the arc energy, the.

  Preferably, the current change rate suppression step converts the converted DC power into high-frequency AC power by a reactor. Preferably, the power insulation step insulates the high-frequency AC power from the AC power source by a high-frequency transformer, and the voltage detection step outputs an output voltage of a reactor provided between the high-frequency transformer and the load device. And the arc suppression step turns off the gate of the power element used in the high-frequency power conversion step when the generation of the arc is detected. Further preferably, the arc suppression step compares the level values of the pulse command waveform and the waveform of the output voltage, and detects the occurrence of an arc when the two level values are different.

  As described above, according to the present invention, the AC power supply device can capture an arc phenomenon at high speed as an AC power supply device such as a film-forming substrate manufacturing apparatus, and can output energy output from a high-frequency power converter. Can be shut off at high speed. Therefore, the arc energy that hinders the product can be minimized. Further, according to the present invention, it is not necessary to provide a differentiation circuit for capturing the arc phenomenon. Therefore, there is no delay due to signal processing of the differentiation circuit, and there is no influence of switching noise generated when generating high-frequency AC power, so that the arc phenomenon can be captured at high speed and with certainty.

The best mode for carrying out the present invention will be described below with reference to the drawings.
〔Constitution〕
First, the configuration of the AC power supply apparatus according to the present invention will be described. FIG. 1 is a control block diagram when the AC power supply apparatus according to the present invention is applied to a film forming substrate manufacturing apparatus. FIG. 2 is a control block diagram showing power control means in the AC power supply apparatus according to the present invention. FIG. 3 is a control block diagram showing oscillation control means in the AC power supply apparatus according to the present invention. As shown in FIG. 1, the film forming substrate manufacturing apparatus 21 includes a commercial AC power source 22, an AC power source device 23, and a load device 24 such as a sputtering device.

  As shown in FIG. 1, the AC power supply device 23 includes an AC-DC rectifier 25, a first smoothing capacitor 26, a DC-DC power converter 27, a second smoothing capacitor 28, and a first current detector 29. , A high frequency power converter 30, a high frequency transformer 31, a reactor 33, a voltage detector 34, a DC control power source 37, a power control means 35, and an oscillation control means 36. The AC power supply device 23 temporarily converts input commercial AC power into DC power, further converts DC power into AC power, and outputs the AC power to the load device 24.

  The AC-DC rectifier 25 is a three-phase full-wave rectifier circuit that uses a rectifying element, for example, a diode, receives three-phase AC power, rectifies the three-phase AC power, and converts the DC power to the first smoothing capacitor 26. Output to. The AC-DC rectifier 25 has an output positive terminal connected to one end of the first smoothing capacitor 26 and an output negative terminal connected to the other end of the first smoothing capacitor. The first smoothing capacitor 26 receives DC power from the AC-DC rectifier 25, smoothes the DC voltage, and outputs the obtained first DC power to the DC-DC power converter 27. The first smoothing capacitor 26 has one end connected to the input positive terminal of the DC-DC power converter 27 and the other end connected to the input negative terminal of the DC-DC converter 27.

  The DC-DC power converter 27 is a switching circuit including a semiconductor switching element, for example, an IGBT (Insulated Gate Bipolar Transistor) (hereinafter referred to as a first switching element) and a DC reactor, and the gate of the first switching element. Is controlled by a control signal (hereinafter referred to as a gate control signal) A input to the collector. The collector and emitter of the first switching element are connected to the negative terminals of the first smoothing capacitor 26 and the second smoothing capacitor 28, respectively. The DC reactor has one end connected to the positive terminal of the first smoothing capacitor 26 and the other end connected to the positive terminal of the second smoothing capacitor 28. That is, the DC-DC power converter 27 receives the first DC power, turns on / off the gate of the first switching element that is present by the gate control signal A, and converts the second DC power to the second DC power. Output to the smoothing capacitor 28.

  The second smoothing capacitor 28 receives the second DC power, smoothes the second DC voltage, and outputs it to the high-frequency power converter 30. The second smoothing capacitor 28 has one end connected to the input positive terminal of the high frequency power converter 30 and the other end connected to the input negative terminal of the high frequency power converter 30. The first current detector 29 is a sensor that detects a current to be measured in a non-contact manner using, for example, a Hall element that is a magnetoelectric conversion element, and an actual direct current on the output side of the DC-DC power converter 27. A value [c] (hereinafter, [] indicates a signal level. For example, the signal level of the signal C indicates [c]) and an overcurrent are detected.

  The high-frequency power converter 30 is an inverter circuit, and is referred to as two pairs of semiconductor switching elements facing each other, for example, a pair of IGBT (Q1 and Q4 switches) and IGBT (Q2 and Q3 switches) (hereinafter referred to as a second switching element). ) Controls the conduction / cutoff between the collector and the emitter by a control signal (hereinafter referred to as a switching control signal) D input to the gate of the second switching element. That is, in the high-frequency power converter 30, the second switching element alternately turns on / off alternately, and the second DC power having a waveform voltage smoothed by the second smoothing capacitor 28 is converted into a substantially rectangular shape. It is a circuit for converting to a first AC power having a voltage of a wave AC waveform. That is, the high-frequency power converter 30 receives the second DC power, turns on / off the gate of the second switching element that is present by the switching control signal D, and converts the second DC power into the first AC power. And the alternating-current power is output to the high-frequency transformer 31.

  The high-frequency transformer 31 is a transformer composed of a primary winding 31p and a secondary winding 31s that are electromagnetically coupled to each other. An AC voltage is input to the primary winding 31p, and the primary winding is caused by mutual electromagnetic induction. An AC voltage proportional to the turn ratio between the line 31p and the secondary winding 31s is generated in the secondary winding 31s. The primary winding 31p of the high-frequency transformer 31 has a winding start connected to the emitter of the second switching element Q1 and the collector of Q3, and an end of winding connected to the emitter of the second switching element Q2 and the collector of Q4. The secondary winding 31 s of the high-frequency transformer 31 is connected to the load device 24. That is, the high-frequency transformer 31 receives the first AC power, converts the first AC power into second AC power that is electrically insulated from the first AC power, and outputs the second AC power to the load device 24. Thus, the high frequency transformer 31 insulates the input commercial power supply from the AC power.

  The reactor 33 is an inductance device for suppressing the current change rate of the output current on the secondary side of the high-frequency transformer 31. The voltage detector 34 is a detector for detecting an output voltage between the high-frequency transformer 31 and the load device 24. The DC control power source 37 is a control constant voltage power source for supplying a DC constant voltage to the DC circuit in the power control means 35 and the oscillation control means 36. In the present embodiment, the DC control power supply 37 receives a two-phase commercial power supply from the commercial AC power supply 22 and outputs a DC constant voltage. However, a power supply of a different system from the commercial AC power supply 22 is used. Thus, a DC constant voltage may be output as a completely independent DC control power source.

  As shown in FIG. 2, the power control unit 35 includes a basic power command value setter 38, a feedback power calculator 39, a subtractor 40, a PID controller 41, and a GATE controller 42. The basic power command value setter 38 is a setter that sets a basic power command value [s] of DC input power that is determined by parameters such as the size of the device, production efficiency, and the like that match the load device 24. The feedback power calculator 39 receives the actual DC voltage value [b] and the actual DC current value [c], and multiplies the actual DC voltage value [b] by the actual DC current value [c]. The obtained feedback power value is output to the subtractor 40.

  The subtractor 40 inputs the basic power command value [s] from the basic power command value setter 38 and the feedback power value from the feedback power calculator 39, and subtracts the feedback power value from the basic power command value [s]. Depending on the result of the calculation, the obtained power deviation value is output to the PID controller 41. The PID controller 41 inputs a power deviation value, performs PID control on the power deviation value, and outputs an operation amount to the GATE controller 42. The GATE controller 42 outputs the gate control signal A to the gate of the first switching element in the DC-DC power converter 27 based on the operation amount by the PID controller 41 that performs PID control according to the power deviation value. That is, the power control means 35 subtracts the feedback power value from the basic power command value [s] commensurate with the load device 24, and based on the power deviation value obtained from the calculation result, the gate control signal A is DC-DC. The power is output to the power converter 27 and the second DC power is controlled by the gate control signal A.

  As shown in FIG. 3, the oscillation control means 36 includes an arc detection means 43 and a pulse command calculation means 44. The arc detection means 43 includes a pulse transformer 45, a differential amplifier 46, an absolute value converter 47, a reference voltage setter 48, a voltage determiner 49, a comparator 50, a latch and cut-off signal generator 51, and a restart signal calculator 52. Is provided.

  The pulse transformer 45 is a wideband transformer for digital signals. The pulse transformer 45 receives the output voltage feedback signal E from the voltage detector 34 and outputs the electrically isolated output voltage feedback signal E to the differential amplifier 46. The pulse transformer 45 is disposed between the voltage detector 34 and the differential amplifier 46, and the winding ratio of the secondary winding 45s and the primary winding 45p of the pulse transformer 45 is, for example, 1: 1. Thereby, the signal of the primary side winding 45p of the pulse transformer 45 and the signal of the secondary side winding 45s can be insulated, and the input / output of the signal can be compared with the oscillation control means not having the pulse transformer 45. Excellent insulation. Furthermore, signal transmission delay can be further reduced as compared with the case where a photocoupler is used instead of the pulse transformer 45.

  The differential amplifier 46 receives the output voltage feedback signal E from the voltage detector 34 via the pulse transformer 45, amplifies the output voltage feedback signal E, and outputs the obtained feedback voltage signal FA to the absolute value converter 47. . The absolute value converter 47 receives the feedback voltage signal FA, calculates the absolute value of the feedback voltage signal FA, and outputs the obtained unipolar feedback voltage signal G to the voltage determiner 49 based on the calculation result. The reference voltage setting unit 48 is a setting unit that sets a constant reference voltage value [n] in order to prevent malfunction of the processing circuit due to electrical noise.

  The voltage determiner 49 receives the reference voltage value [n] and the unipolar feedback voltage signal level [g], compares the reference voltage value [n] with the feedback voltage signal level [g], and returns the feedback voltage signal. The feedback pulse signal H is output to the comparator 50 when the level [g] is equal to or greater than the reference voltage value [n], and zero is output when the level [g] is smaller. The comparator 50 receives the unipolar pulse command signal J from the pulse command calculation means 44 and the unipolar feedback pulse signal H edited from the output voltage feedback signal E, and receives the pulse command signal J and the feedback pulse signal H. And the arc detection signal K is output to the latch and cut-off signal generator 51 only when the voltage of the feedback pulse signal H is different from the voltage of the pulse command signal J. In this case, the comparator 50 determines that the voltages are different when the voltage difference between the pulse command signal J and the feedback pulse signal H is not within a predetermined range, and outputs the arc detection signal K.

  The latch and cutoff signal generator 51 inputs the arc detection signal K and stores the arc detection signal K, thereby outputting the cutoff signal L to the output cutoff switch 57 and the restart signal calculator 52. Thereby, the high frequency power converter 30 can interrupt the output power of the high frequency power converter 30 at high speed by interrupting the switching command signal I and thereby interrupting the second switching element. The restart signal calculator 52 receives the cutoff signal L, and outputs the restart signal M to the latch and cutoff signal generator 51 after a predetermined time. Thereby, the interruption signal L output from the latch and interruption signal generator 51 is reset after a predetermined time in order to detect the next arc detection signal K.

  The pulse command calculation means 44 includes a switching frequency setter 53, a dead band setter 54, a switching signal generator 55, an absolute value converter 56, an output cutoff switch 57, a P-side element drive circuit 58, and an N-side element drive circuit 59. Is provided. The switching frequency setting unit 53 is a setting unit that sets the switching frequency command value [p] of the switching command signal I for turning on / off the gate of the second switching element. The dead band setting unit 54 is a setting unit that sets a dead band period [q] for surely turning off the second switching element when switching the P-side and N-side pulse signals of the switching command signal I. is there.

  The switching signal generator 55 receives the switching frequency command value [p] and the dead band period [q], generates the switching command signal I from the switching frequency command value [p] and the dead band period [q], The switching command signal I is output to the absolute value converter 56 and the output cutoff switch 57. The absolute value converter 56 receives the switching command signal I, calculates the absolute value of the switching command signal I, and supplies the obtained unipolar pulse command signal J to the comparator 50 of the arc detection means 43 based on the calculation result. Output.

  The output cut-off switch 57 receives the switching command signal I, cuts off the switching command signal I by the cut-off signal L from the latch and cut-off signal generator 51, and drives the drive circuit 58 for the P-side element and the drive circuit for the N-side element. The control signal R output to 59 is cut off. The P-side element drive circuit 58 receives the control signal R and outputs a switching control signal D (P) for driving the P-side second switching element by the control signal R to the high-frequency power converter 30. The N-side element drive circuit 59 receives the control signal R and outputs a switching control signal D (N) for driving the N-side second switching element to the high-frequency power converter 30 by the control signal R.

[Arc suppression method]
Next, an arc suppression method in the AC power supply apparatus according to the present invention will be described. FIG. 4 is a flowchart showing the processing procedure of the arc suppression method in the AC power supply according to the present invention. The arc suppression method in the AC power supply device 23 generates DC power from a commercial AC power supply (S-1). The DC power is converted to DC power suitable for the load device (S-2). The converted DC power is converted into high-frequency AC power (S-3). The high-frequency AC power is insulated from the AC power supply (S-4). The change rate of the output current obtained from the high-frequency AC power is suppressed (S-5). The output voltage to the load device 24 is detected (S-6). The generation of the arc is detected at high speed from the output voltage, and the high-frequency AC power is cut off at high speed (S-7). Thereby, the arc phenomenon can be captured at high speed, and the energy output from the high-frequency power converter 30 can be interrupted at high speed. Therefore, the arc energy that hinders the product can be minimized.

[Operation]
Next, the operation of the AC power supply device 23 according to the present invention will be described. First, the overall operation of the AC power supply device 23 will be described. The AC-DC rectifier 25 rectifies AC power of the commercial AC power supply 22 and outputs DC power. The first smoothing capacitor 26 smoothes the DC voltage based on the DC power and outputs the first DC power. The DC-DC power converter 27 converts the first DC power to the second DC power. That is, the DC-DC power converter 27 receives the first DC power, and turns on the gate of the first switching element inherent in the DC-DC power converter 27 by the gate control signal A by the power control means 35. / Off control, constant DC voltage, current and power (hereinafter collectively referred to as power) are controlled to output second DC power.

  The second smoothing capacitor 28 smoothes the second DC voltage based on the second DC power, and outputs the smoothed second DC power. The high frequency power converter 30 converts the smoothed second DC power into high frequency AC power. That is, the high-frequency power converter 30 inputs the smoothed second DC voltage, and the gate of the second switching element inherent in the high-frequency power converter 30 is transferred at high speed by the switching control signal D from the oscillation control means 36. Switch and output high-frequency AC power. The high frequency transformer 31 electrically insulates the output high frequency AC power from the input commercial power source. The high frequency transformer 31 is installed as necessary, and supplies the insulated high frequency AC power to the load device 24.

  Next, the operation of the power control unit 35 will be described. As shown in FIG. 1 and FIG. 2, the power control means 35 inputs the actual DC voltage value [b] and the actual DC current value [c] from the first current detector 29, and the basic power command value setter The gate control signal A for operating the first switching element is output to the DC-DC power converter 27 in accordance with the basic power command value [s] by 38.

  When the actual DC voltage value [b] and the actual DC current value [c] are input to the feedback power calculator 39, the feedback power calculator 39 multiplies the actual DC voltage value [b] and the actual DC current value [c]. The actual feedback power value obtained is output to the subtractor 40. The subtractor 40 subtracts the actual feedback power value from the basic power command value [s] and outputs the obtained power deviation value to the PID controller 41. The PID controller 41 causes the power deviation value to be proportionally operated, the integration operation for changing the input value in proportion to the integration of the power deviation value, and the differentiation for changing the input value in proportion to the differentiation of the power deviation value. Control that combines the operations is performed, and the operation amount is output to the GATE controller 42. In this case, only the PI operation may be controlled instead of the PID operation.

  The GATE controller 42 outputs a gate control signal A to the gate of the first switching element based on the operation amount by the PID controller 39. That is, when the power deviation value increases, control is performed so that the ON operation time of the gate control signal A becomes longer, and when the power deviation value decreases, control is performed so that the ON operation time of the gate control signal A becomes shorter. Thereby, the power control means 35 can control the input DC power to a constant DC power.

  Next, the operation of the oscillation control means 36 will be described. FIG. 5 is a diagram showing the relationship between the signal waveform of each control block and the elapsed time in the AC power supply apparatus according to the present invention. FIG. 5E is a diagram showing the relationship between the output voltage feedback signal and the elapsed time, where the horizontal axis indicates the elapsed time and the vertical axis indicates the output voltage feedback signal. FIG. 5G is a diagram showing the relationship between the absolute value of the feedback voltage signal and the elapsed time. The horizontal axis indicates the elapsed time, and the vertical axis indicates the absolute value of the feedback voltage signal. FIG. 5 (H ′) is a diagram illustrating the relationship between the feedback pulse preliminary signal and the elapsed time, where the horizontal axis indicates the elapsed time and the vertical axis indicates the feedback pulse preliminary signal. FIG. 5H is a diagram showing the relationship between the feedback pulse signal and the elapsed time. The horizontal axis represents the elapsed time, and the vertical axis represents the feedback pulse signal. Here, for comparison with the reference command (pulse command signal J), the feedback pulse signal H is a signal obtained by correcting the peak value of the waveform of the feedback pulse preliminary signal H ′ so as to be the same level as the peak value of the reference command. It is. FIG. 5I is a diagram illustrating the relationship between the switching command signal and the elapsed time, where the horizontal axis indicates the elapsed time and the vertical axis indicates the switching command signal. FIG. 5J is a diagram showing the relationship between the absolute value of the switching command signal and the elapsed time. The horizontal axis represents the elapsed time, and the vertical axis represents the absolute value of the switching command signal. FIG. 5K is a diagram illustrating the relationship between the arc detection signal and the elapsed time. The horizontal axis represents the elapsed time, and the vertical axis represents the arc detection signal. This waveform is a waveform obtained by comparing the feedback pulse signal H and the pulse command signal J. FIG. 5 (L / M) is a diagram illustrating the relationship between the cutoff signal and the restart signal and the elapsed time. The horizontal axis represents the elapsed time, and the vertical axis represents the cutoff signal and the restart signal.

  FIG. 6 is a diagram showing the relationship between the enlarged view of the signal waveform and the elapsed time in the AC power supply according to the present invention. FIG. 6J is a diagram showing the relationship between the pulse command signal and the elapsed time. T1 is the period of the pulse command signal, for example, indicating 20 microseconds, and T2 is the dead band period, for example, indicating 6 microseconds. T3 is a delay in signal processing time mainly by the high-frequency power converter 30 including the second switching element, and indicates 4 microseconds, for example. T4 is a dead zone in which the comparator 50 does not detect an arc, and indicates, for example, 6 microseconds by adding a margin time (for example, 2 microseconds) to the time delay. FIG. 6H is a diagram illustrating the relationship between the feedback pulse signal and the elapsed time. Point T is the time at which the level of the feedback pulse signal H starts to change suddenly with respect to the pulse command signal J, for example, the time at which the level V1 starts to change to zero. FIG. 6K is a diagram illustrating the relationship between the arc detection signal and the elapsed time. Point U indicates the time when the pulsed arc detection signal starts to be detected. FIG. 6 (L / M) is a diagram illustrating the relationship between the cutoff signal and the restart signal and the elapsed time. Point V indicates the time when the interruption signal starts to be output based on the arc detection signal. Point W indicates the time when the restart signal starts to be output.

  When the output voltage feedback signal E from the voltage detector 34 is input to the pulse transformer 45 of the arc detection means 43, the output voltage feedback signal E that is electrically insulated by the pulse transformer 45 is output to the differential amplifier 46. When the electrically isolated output voltage feedback signal E is input to the differential amplifier 46, the differential amplifier 46 amplifies the output voltage feedback signal E and outputs the feedback voltage signal FA to the absolute value calculator 47. When the feedback voltage signal FA from the differential amplifier 46 is input to the absolute value calculator 47, the absolute value calculator 47 outputs a feedback voltage signal G having a unipolar feedback voltage signal FA to the voltage determiner 49. Thus, common mode noise can be reduced when electrical noise is superimposed on the voltage on the high voltage side with respect to the ground of the wiring path.

  When the unipolar feedback voltage signal G and the predetermined reference voltage signal N from the reference voltage setting unit 54 are input to the voltage determiner 49, the voltage determiner 49 generates the unipolar feedback voltage signal G and the reference voltage signal N. In comparison, when the voltage value of the unipolar feedback voltage signal G exceeds the voltage value of the reference voltage signal N, the feedback pulse signal H is output to the comparator 50. In practice, however, the feedback pulse signal H from the voltage determiner 49 is preliminarily amplified in voltage so that the output voltage can be compared with the pulse command signal J. As a result, the feedback voltage signal G is compared with a constant reference voltage value, and only a signal exceeding the constant value is sent to the next process, so that malfunction of the processing circuit due to electrical noise can be prevented.

  When the feedback pulse signal H from the voltage determiner 49 and the pulse command signal J from the pulse command calculation means 44 are input to the comparator 50, the comparator 50 causes the level value of the feedback pulse signal H to be set to the level value of the pulse command signal J. Only when they are different, the arc detection signal K is output to the latch and interruption signal generator 51. In this case, the comparator 50 is set not to perform, for example, a comparison operation between the feedback pulse signal H and the pulse command signal J in the dead zone T4. That is, when the feedback pulse signal H changes, the comparator 50 performs a comparison operation between the changed feedback pulse signal H and the pulse command signal J after the dead zone T4 has elapsed. This is because, in FIG. 6, the dead zone T4 is a section where the signal level of the pulse command signal J exists, and a time delay due to the second switching element occurs at the rising portion of the feedback pulse signal H. This is because it is a section (including a margin section), and when the magnitude comparison between the pulse command signal J and the feedback pulse signal H is performed in this section T4, the arc is erroneously detected. . Thereby, an arc can be detected for every half cycle (excluding the dead zone T4) of the AC power supplied to the load device 24. That is, if the signal frequency of the output voltage feedback signal E is 20 KHz, for example, an arc can be detected every 25 microseconds.

  In the above description, the pulse command signal J and the feedback pulse signal H are respectively sent to the comparator 50 through the absolute value converter 56 and the absolute value converter 47 and compared, but the switching signal generator 55 The switching command signal I and the feedback voltage signal FA may be directly compared with a plus or minus waveform. The comparator 50 may perform a comparison operation using a digital circuit, a high-speed arithmetic element, or software.

  When the arc detection signal K from the comparator 50 is input to the latch and interruption signal generator 51, the signal processing time by the latch and interruption signal generator 51 is delayed, and the output time is slightly delayed with respect to the arc detection signal K. The cutoff signal L is output to the restart signal calculator 52 and the output cutoff switch 57. When the shut-off signal L from the latch and shut-off signal generator 51 is input to the restart signal calculator 52, the restart signal calculator 52 operates the timer built in the restart signal calculator 52, as shown in FIG. After a predetermined time T5 has elapsed, the timer is turned off, and the restart signal M is output to the latch and shut-off signal generator 51. Thereby, the latch and interruption signal generator 51 cancels and resets the interruption signal L after a predetermined time in order to detect the arc detection signal again.

  Further, when the cutoff signal L is input to the output cutoff switch 57 of the pulse command calculation means 44, the output cutoff switch 57 switches from on to off, shuts off the switching command signal I, and turns off the control signal R. Is output to the P-side element drive circuit 58 and the N-side element drive circuit 59. When the OFF signal from the output cutoff switch 57 is input to the P-side element drive circuit 50 and the N-side element drive circuit 51 that drive the second switching element, the P-side element drive circuit 50 and the N-side element drive circuit 51 The switching control signal for turning on / off the gate of the second switching element is changed from the on state to the off state, and the AC power to the load device 24 is interrupted.

  As described above, according to the present invention, the oscillation control means 36 of the AC power supply device 23 generates the feedback pulse signal H for the AC power supplied to the load device 24 based on the output voltage feedback signal E of the AC power. For the switching control signal D output to the high-frequency power converter 30, a pulse command signal J is generated based on the switching command signal I that is the source of the switching control signal D, and the feedback pulse signal H and the pulse command are generated. Compared with the signal J, when the level values of these signals are different, an interruption signal L is generated as an arc is detected. In this case, when no arc is generated, the level values of the feedback pulse signal H and the pulse command signal J are equal, so that the cutoff signal L is not generated. On the other hand, when an arc occurs, the voltage of the output voltage feedback signal E decreases, and the cutoff signal L is generated because the level values of the feedback pulse signal H and the pulse command signal J are different. That is, since this interruption signal L is determined and generated every ½ period of the output voltage feedback signal E in the AC power, the generation of the arc occurs every ½ period of the AC power supplied to the load device 24. Can be detected. As a result, the AC power supply device 23 can capture the arc phenomenon at a high speed as the AC power supply device of the film forming substrate manufacturing apparatus 21 and can cut off the energy output from the high-frequency power converter 30 at a high speed. . Therefore, the arc energy that hinders the product can be minimized.

  Further, according to the present invention, when the reactor 33 is inserted between the high frequency transformer 31 and the load device 24 and the voltage detector 34 views the load device 24 from the high frequency transformer 31 as shown in FIG. The voltage after the reactor 33 was detected. Thereby, the vibration of the waveform of the output voltage of the high frequency transformer 31 can be suppressed. FIG. 7 is a diagram illustrating voltage waveforms before and after the reactor 33 when the reactor 33 is inserted between the high-frequency transformer 31 and the load device 24. When the voltage waveform before the reactor 33 shown in FIG. 7 (1) is compared with the voltage waveform after the reactor 33 shown in (2), the voltage waveform (2) after the reactor 33 suppresses voltage oscillation. I understand that. Thus, since the voltage detector 34 can detect an output voltage with less vibration, the AC power supply device 23 can capture the arc phenomenon at high speed and reliably. The rate of change in the output current of the high frequency transformer 31 can be suppressed by inserting the reactor 33 between the high frequency transformer and the load device 24, and the voltage detector 34 is connected to the high frequency transformer 31 and the load device 24. Can be detected, and the arc phenomenon can be detected.

It is a control block diagram at the time of applying the alternating current power supply device which concerns on this invention to the board | substrate manufacturing apparatus for film-forming. It is a control block diagram which shows the electric power control means in the alternating current power supply device which concerns on this invention. It is a control block diagram which shows the oscillation control means in the alternating current power supply device which concerns on this invention. It is a flowchart figure which shows the process sequence of the arc suppression method in the alternating current power supply device which concerns on this invention. It is a figure which shows the relationship between the signal waveform of each control block and elapsed time in the alternating current power supply device which concerns on this invention. It is a figure which shows the relationship between the enlarged view of the signal waveform in the alternating current power supply device which concerns on this invention, and elapsed time. It is a figure which shows the voltage waveform before and behind a reactor. It is a figure which shows the structure of the apparatus in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC control part 2 Smoothing circuit 3 Inverter switching part 4 Step-up transformer 5 Rectification part 6 Discharge voltage detection circuit 7 Current transformer 8 Discharge voltage fall detection circuit 9 Arc determination comparison circuit 10 Gate drive 11 Inverter control part 12 Processing apparatus main body 13 Thyristor Control unit 21 Deposition substrate manufacturing apparatus 22 Commercial AC power supply 23 AC power supply apparatus 24 Load apparatus 25 AC-DC rectifier 26 First smoothing capacitor 27 DC-DC power converter 28 Second smoothing capacitor 29 First Current detector 30 High-frequency power converter 31 High-frequency transformer 33 Reactor 34 Voltage detector 35 Power control means 36 Oscillation control means 37 DC control power supply 38 Basic power command value setter 39 Feedback power calculator 40 Subtractor 41 PID controller 42 GATE controller 43 Arc detection means 44 Pulse command performance Means 45 Pulse transformer 46 Differential amplifier 47 Absolute value converter 48 Reference voltage setter 49 Voltage determiner 50 Comparator 51 Latch and cut-off signal generator 52 Restart signal calculator 53 Switching frequency setter 54 Deadband setter 55 Switching Signal generator 56 Absolute value converter 57 Output cutoff switch 58 P-side element drive circuit 59 N-side element drive circuit A Gate control signal B Actual DC voltage signal C Actual DC current signal D Switching control signal E Output voltage feedback signal FA Feedback Voltage signal G Unipolar feedback voltage signal H Feedback pulse signal I Switching command signal J Pulse command signal K Arc detection signal L Shutdown signal M Restart signal N Reference voltage signal P Switching frequency command value signal Q Deadband period signal

Claims (8)

A power source for supplying high-frequency AC power converted from commercial AC power to the electrodes in the load device, wherein the AC power source device suppresses arcs generated between the electrodes .
An AC-DC rectifier for generating DC power from the commercial AC power;
A DC-DC power converter for converting the DC power into DC power suitable for a load;
A high-frequency power converter that converts the converted DC power into high-frequency AC power;
A high-frequency transformer for insulating the high-frequency AC power from a commercial AC power source;
Current rate-of-change suppression means for suppressing the rate of change of current obtained from the insulated high-frequency AC power;
A voltage detector for detecting an output voltage to the load device in the insulated high-frequency AC power;
Compare the pulse command waveform for driving the power element of the high-frequency power converter and the waveform of the output voltage, detect the occurrence of arc when both waveforms are different, and supply the high-frequency AC power to the load device Arc suppression means for blocking and suppressing arc energy;
An AC power supply device comprising:   The AC power supply apparatus according to claim 1, wherein the current change rate suppression means is a reactor. The voltage detector detects an output voltage of a reactor provided between the high-frequency transformer and the load device,
The AC power supply apparatus according to claim 2, wherein the arc suppression means turns off the gate of the power element of the high-frequency power converter when the generation of the arc is detected.   2. The AC power supply apparatus according to claim 1, wherein the arc suppression means compares the level values of the pulse command waveform and the waveform of the output voltage, and detects the occurrence of an arc when the two level values are different. . A method of suppressing an arc more AC power supply for supplying high-frequency AC power converted from the commercial AC power to the electrodes in the load device, generated between the electrodes,
AC-DC rectification process for generating DC power from the commercial AC power;
A DC-DC power conversion step of converting the DC power into DC power suitable for a load;
A high-frequency power conversion step of converting the converted DC power into high-frequency AC power;
A power insulating step for insulating the high-frequency AC power from the AC power source;
A current change rate suppressing step of suppressing a change rate of a current obtained from the insulated high-frequency AC power;
A voltage detection step of detecting an output voltage to the load device in the insulated high-frequency AC power;
Compare the pulse command waveform for driving the power element used in the high-frequency power conversion step with the waveform of the output voltage, detect the occurrence of arc when the two waveforms are different, and supply high-frequency AC power to the load device An arc suppression process that interrupts and suppresses arc energy;
An arc suppression method comprising:   The arc suppression method according to claim 5, wherein the current change rate suppression step converts the converted DC power into high-frequency AC power by a reactor. In the power insulation step, the high-frequency AC power is insulated from the AC power source by a high-frequency transformer,
The voltage detection step detects an output voltage of a reactor provided between the high-frequency transformer and the load device,
The arc suppression method according to claim 6, wherein the arc suppression step turns off a gate of a power element used in the high-frequency power conversion step when the generation of the arc is detected.   6. The arc suppression method according to claim 5, wherein the arc suppression step compares the level values of the pulse command waveform and the waveform of the output voltage, and detects the occurrence of an arc when the two level values are different. .

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