JP2002263472A - Plasma processor and plasma processing method using inverter circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the miniaturized plasma processor of high energy efficiency by which the power loss of the protective resistor of an impulse circuit is reduced. SOLUTION: An inverter circuit S1 generates the rectangular wave AC voltage of a high frequency from a commercial AC voltage. Then, the pulse transformer 31 of a small capacity generates a high frequency high voltage by boosting the rectangular wave AC voltage and a full wave rectifier 34 generates a DC high voltage in a pulsating current shape by full-wave rectifying the high frequency high voltage. Thereafter, the impulse circuit S4 generates the pulse voltage of a high voltage/a high frequency from the DC high voltage, applies it between a discharge electrode 1 and a counter electrode 2 and generates corona discharges and then plasma 3. Since the pulse transformer 31 is of small capacity, the plasma processor is miniaturized. Since the DC high voltage is in the pulsating current shape, the power loss of the protective resistor is reduced and the energy efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corona generated by a pulsed voltage by applying a pulse voltage generated from commercial AC power by a DC high voltage generating circuit and an impulse circuit between a discharge electrode and a counter electrode. The present invention relates to a plasma processing apparatus and a plasma processing method for irradiating an object to be processed with plasma generated by discharge to improve the surface characteristics thereof, and particularly relates to a method of connecting a commercial AC power supply and a DC high voltage generation circuit. By installing an inverter circuit,
The present invention relates to a plasma processing apparatus and a plasma processing method that reduce the size of a DC high voltage generation circuit and reduce the power loss of a protection resistor of an impulse circuit.

[0002]

2. Description of the Related Art Generally, resin (plastic), paper,
Painting, printing, etc. on members made of materials such as cloth and metal,
Alternatively, when bonding to another object, the member is often subjected to a surface treatment in order to enhance the paintability, printability, adhesiveness, hydrophilicity, hygroscopicity and the like of the surface of the member. Then, as one of such surface treatment methods, a plasma treatment in which plasma generated by corona discharge in the air is applied to the member (hereinafter, referred to as “object to be treated”) to modify the surface thereof. (Corona discharge treatment) is known.

In a plasma processing apparatus for performing plasma processing on an object to be processed as described above, a high-voltage / high-frequency pulse voltage generated by a pulse generation circuit is generally provided between a discharge electrode and a counter electrode facing each other. Is applied to cause a corona discharge between the two electrodes to generate plasma in the air. The object to be processed is arranged between the two electrodes in a stationary state or a moving state, and the surface thereof is subjected to plasma processing (for example, see Japanese Patent Application Laid-Open No. 5-33997). Such a plasma processing apparatus includes, for example, a DC high voltage generation circuit that generates a DC high voltage from a commercial AC voltage (power), an impulse circuit (pulse generation circuit) that generates a pulse voltage from a DC high voltage, and a pulse voltage. A plasma processing unit for applying a voltage between the electrodes (for example, see Japanese Patent Application Laid-Open No. 8-164320).

More specifically, as shown in FIG. 4, a conventional plasma processing apparatus of this type includes a DC high voltage generation circuit T1.
, An impulse circuit T2, and a plasma processing unit T3. Then, in the plasma processing unit T3, the discharge electrode 101 and the counter electrode 102 are opposed to each other at a predetermined interval, and a high-voltage / high-frequency pulse voltage is applied between the electrodes 101 and 102 from the impulse circuit T2. The plasma 103 is generated by the corona discharge.

[0005] The impulse circuit T2 has a positive lead 104 connected at one end to the positive output terminal of the DC high voltage generating circuit T1 and the other end connected to the discharge electrode 101, and one end connected to the DC high voltage generating circuit T1. Negative conductor 1 connected to a negative output terminal and the other end connected to counter electrode 102
05 is provided. Then, the positive conductor 104
Is provided with a protection resistor 106. In addition, an inductance coil 108 and a gap switch 109 are provided in series on a connection conductor 107 that connects the plus conductor 104 and the minus conductor 105. further,
A charge / discharge capacitor 110 is interposed in the positive conductor 104. Further, a load resistor 112 is interposed in another connection conductor 111 that connects the plus conductor 104 and the minus conductor 105. Note that the DC high voltage generation circuit T1 is provided with a transformer 113 that generates an AC high voltage from commercial AC power, and a full-wave rectifier 114 that performs full-wave rectification of the AC high voltage.

Thus, in the plasma processing apparatus or the plasma processing method using the same, when a high DC voltage is applied from the DC high voltage generation circuit T1 to the impulse circuit T2, the DC high voltage is applied to the charge / discharge capacitor 110.
And charge is accumulated in the charge / discharge capacitor 110. In parallel with this, the voltage applied to the gap switch 109 also rises sharply. And the charge / discharge capacitor 11
Almost at the same time as the electric charge is accumulated to the saturation state at 0, a spark discharge occurs between the two spherical electrodes of the gap switch 109. The gap switch 109 becomes conductive by this spark discharge, and the electric charge stored in the charge / discharge capacitor 110 is released almost instantaneously.

[0007] The electric charge is determined by the ratio of the capacitance of the charge / discharge capacitor 110 to the capacitance of the space between the discharge electrode 101 and the counter electrode 102, and the inductance of the inductance coil 108. A pulse voltage having a waveform determined by the resistance value of the load resistor 112 is applied between the discharge electrode 101 and the counter electrode 102. Such a process is repeated, and corona discharge is caused between the discharge electrode 101 and the counter electrode 102 to generate the plasma 103.

[0008]

Generally, in this type of plasma processing apparatus, the peak value of the pulse voltage required to induce corona discharge between the discharge electrode and the counter electrode is determined by the distance between the electrodes. However, even when the distance between the electrodes is several cm or less (for example, when a thin object, for example, a sheet-like object is subjected to plasma processing) (pulse frequency: 300 pps or more), the value becomes considerably high. (For example, 50-100 KV). In order to generate such a pulse voltage in the impulse circuit, a very high DC voltage (for example, about 0.7 to 0.8 times the required pulse voltage) is generated in the DC high voltage generation circuit. It is necessary to apply this to the impulse circuit.

However, in a conventional plasma processing apparatus including a DC high voltage generating circuit, an impulse circuit, and a plasma processing unit or a plasma processing method using the same,
If such a DC high voltage generation circuit attempts to generate such a DC high voltage, the DC high voltage generation circuit becomes large-sized or large-capacity, and as a result, the plasma processing apparatus becomes large in size and the manufacturing cost increases. There is. Further, in this type of conventional plasma processing apparatus or a plasma processing method using the same, there is a problem that a power loss (heat loss) at a protection resistor which is a component of the impulse circuit is large and energy efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to reduce the size of a DC high-voltage generation circuit and to reduce the power loss of a protection resistor of an impulse circuit. It is an object of the present invention to provide a small-sized plasma processing apparatus or a plasma processing method which is inexpensive and has high energy efficiency.

[0011]

According to the present invention, there is provided a plasma processing apparatus comprising:
A pulse voltage is applied between the discharge electrode and a counter electrode facing the discharge electrode to generate plasma by corona discharge, and the object is irradiated (applied) with the plasma to perform a surface modification treatment. (Ii) from a single-phase or three-phase commercial AC voltage (power),
An inverter circuit for generating a high-frequency voltage (for example, a rectangular-wave AC voltage) having a higher frequency than the commercial AC voltage;
(Iii) a pulse transformer that boosts a high-frequency voltage generated by the inverter circuit to generate a high-frequency high voltage;
(Iv) a full-wave rectifier circuit for full-wave rectifying the high-frequency high voltage generated by the pulse transformer to generate a DC high voltage;
(V) An impulse circuit for generating a pulse voltage from a DC high voltage generated by the full-wave rectifier circuit and applying the pulse voltage between the discharge electrode and the counter electrode is provided.

Generally, in a transformer, the higher the frequency of the input voltage, the higher the efficiency and the size of the transformer is reduced. According to this plasma processing apparatus, since the high frequency voltage generated by the inverter circuit is input to the pulse transformer, the pulse transformer is significantly reduced in size or capacity, and the plasma processing apparatus is further reduced in size. , The manufacturing cost is reduced. Also,
DC high voltage input from full-wave rectifier circuit to impulse circuit is DC but pulsating (not smooth DC)
Therefore, the power loss (heat generation loss) at the protection resistor of the impulse circuit is reduced, and the energy efficiency of the impulse circuit and thus the plasma processing apparatus is increased.

In the above plasma processing apparatus, it is preferable that the impulse circuit is substantially constituted by a protection resistor, an inductance coil, a charge / discharge capacitor, a gap switch, and a load resistor. In the above plasma processing apparatus, the peak value of the pulse voltage generated by the impulse circuit is set to 50 to 100 KV,
It is preferable that the pulse width is set to 0.5 to 20 μsec and the pulse frequency is set to 95 to 3000 pps, while the electric field strength between both electrodes is set to 4 to 150 KV / cm. Note that these values can be set according to the type and shape of the object to be processed.

[0014] The plasma processing method according to the present invention comprises:
(I) A pulse voltage is applied between a discharge electrode and a counter electrode facing each other (facing each other) to generate plasma by corona discharge, and the object is irradiated (applied) with the plasma to modify the surface. A plasma processing method for performing a process, comprising: (ii) using an inverter circuit to convert a single-phase or three-phase commercial AC voltage (power) to a high-frequency voltage having a higher frequency than the commercial AC voltage (for example, (Iii) generate a high-frequency high voltage by boosting the high-frequency voltage generated by the inverter circuit using a pulse transformer, and (iv) use a pulse transformer using a full-wave rectifier circuit. (V) using an impulse circuit to generate a pulse voltage from the DC high voltage generated by the full-wave rectifier circuit, versus It is characterized in that it is applied between the counter electrode and the counter electrode.

According to this plasma processing method, since the high frequency voltage generated by the inverter circuit is input to the pulse transformer, the pulse transformer is significantly reduced in size or capacity, and the manufacturing cost is reduced. Also, the high DC voltage input from the full-wave rectifier circuit to the impulse circuit is DC but pulsating, so that power loss (heat loss) at the protection resistor of the impulse circuit is reduced, and the energy of the impulse circuit is reduced. Efficiency is increased.

In the above-mentioned plasma processing method, the peak value of the pulse voltage of the pulse generation circuit is set to 50 to 100 KV.
, The pulse width is set to 0.5 to 20 μsec,
It is preferable that the pulse frequency is set to 95 to 3000 pps while the electric field strength between both electrodes is set to 4 to 150 KV / cm. Note that these values can be set according to the type and shape of the object to be processed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. As shown in FIG. 1, a plasma processing apparatus (surface modification processing apparatus) according to the present invention converts a single-phase or three-phase commercial AC power (for example, frequency: 50/60 Hz, voltage: 100/200 V) to a high frequency. An inverter circuit S1 for generating a rectangular wave AC voltage and a pulse voltage generating circuit S2 for generating a pulse voltage from the rectangular wave AC voltage are provided. Note that the pulse voltage generation circuit S2 is a DC high voltage generation circuit S that generates a DC high voltage from a rectangular wave AC voltage.
3 and an impulse circuit S4 for generating a pulse voltage from a DC high voltage. The plasma processing apparatus further includes a plasma processing unit S5 for generating a plasma by inducing a corona discharge by a pulse voltage, irradiating the plasma to an object to be processed, and performing a surface modification process.

The plasma processing section S5 is provided with a discharge electrode 1 and a counter electrode 2 arranged opposite to the discharge electrode 1. Here, both electrodes 1 and 2 are placed in air under atmospheric pressure and have an appropriate distance between the electrodes in accordance with the shape or size of the object to be processed (not shown) (for example, in the case of a thin object, approximately 5 cm or less). Are arranged opposite to each other. That is, the electrodes 1 and 2 are arranged with an appropriate inter-electrode distance between them so that the object to be processed can be positioned in a stationary state or a moving state.

A high voltage and high frequency pulse voltage generated by the impulse circuit S4 is applied between the discharge electrode 1 and the counter electrode 2. When a pulse voltage is applied between the electrodes 1 and 2, a corona discharge is induced in a space between the electrodes 1 and 2, and the plasma 3 is generated by the corona discharge. As described above, the plasma 3 generated in the space between the electrodes 1 and 2 is irradiated (applied) to the processing object located between the electrodes 1 and 2, and as a result, the surface of the processing object Is modified by the plasma 3 to improve its paintability, printability, adhesiveness, hygroscopicity, hydrophilicity and the like.
Examples of the object to be treated that can be modified by the plasma 3 include a resin molded product (plastic molded product), a resin sheet (plastic sheet), a resin film (plastic film), paper, cloth, nonwoven fabric, and the like. Examples include a metal plate.

The impulse circuit S4 has a positive main conductor 4 having one end connected to the positive output terminal of the DC high voltage generating circuit S3 and the other end connected to the discharge electrode 1, and one end connected to the DC high voltage generating circuit S3. Negative main conductor 5 connected to the negative output terminal of
Are provided. And the plus side main conductor 4
Of the protective resistance 6 is interposed on the power supply side of a branch portion P _1. Also, the branch portion P ₁ of the plus side main conductor 4
The first connecting wire 7 for connecting the branch portion P ₂ of the negative-side main conductor 5, from the P ₁ side P ₂ side in this order and,
An inductance coil 8 and a gap switch 9 are interposed in series. The gap switch 9 includes a plus-side ball electrode 9a and a minus-side ball electrode 9b that are opposed to each other with a predetermined distance between the electrodes. Moreover, the positive-side main conductor 4, in a portion between the branch portion P ₁ and the branch portion P _3, charging and discharging the capacitor 10 is interposed. Also, the branch portion P of the plus side main conductor 4
₃ and the negative load resistor 12 to the second connecting wire 11 that connects the branch portion P ₄ in the main conductor 5 is interposed.

Thus, in the impulse circuit S4, a high-voltage pulse voltage whose voltage oscillates (fluctuates) with high frequency is generated by the following process. That is, when a DC high voltage is applied from the DC high voltage generation circuit S3 to the impulse circuit S4, the DC high voltage is applied to the charge / discharge capacitor 10 via the protection resistor 6, and the charge / discharge capacitor 10
The electric charge is accumulated (charged). In parallel with this,
The voltage between the two ball electrodes 9a and 9b of the gap switch 9 rises sharply.

After the electric charge is accumulated in the charge / discharge capacitor 10 until it is almost saturated, the two ball electrodes 9 of the gap switch 9
When the voltage between a and 9b exceeds the spark generation voltage, a spark discharge (spark) is generated between the two spherical electrodes 9a and 9b.
The voltage at which the spark discharge occurs depends on the two ball electrodes 9a, 9b.
(Discharge gap). The gap switch 9 becomes conductive or short-circuited by this spark discharge,
The charge stored in the charge / discharge capacitor 10 is released almost instantaneously. Thus, the impulse circuit S4 determines the voltage value determined by the ratio of the capacitance of the charge / discharge capacitor 10 and the capacitance of the space between the two electrodes 1 and 2, the inductance value of the inductance coil 8 and the load resistance 12 A pulse voltage having a waveform determined by the resistance value is generated. The protection resistor 6 is connected to the DC high-voltage circuit S when the gap switch 9 is turned on or short-circuited.
The output terminals 3 are short-circuited to prevent an excessive current from flowing between them.

The pulse voltage generated by the impulse circuit S4 is applied between the discharge electrode 1 and the counter electrode 2. This process is repeated,
A high-voltage and high-frequency pulse voltage is stably applied between the discharge electrode 1 and the counter electrode 2, corona discharge is induced between the electrodes 1 and 2, and plasma 3 is generated.

Here, the peak value of the pulse voltage to be applied to generate corona discharge between the discharge electrode 1 and the counter electrode 2 to generate the plasma 3 is determined by the discharge electrode 1
Although it depends on the distance between the electrode and the counter electrode 2 (distance between the electrodes), if the distance between the electrodes is 5 cm or less (in the case of a plasma treatment of a thin object), it is preferably within a range of about 50 to 100 KV. The electric field strength between both electrodes 1 and 2 is 4 to 1
It is preferably 50 KV / cm. The pulse frequency of the pulse voltage is preferably about 95 to 3000 pps, and the pulse width is preferably about 0.5 to 20 μm. In order to generate a pulse voltage in the impulse circuit S4, the pulse voltage is approximately 0.7 to 0.7.
It is necessary to apply eight times the DC high voltage from the DC high voltage generation circuit S3 to the impulse circuit S4.

Hereinafter, specific configurations and functions of the inverter circuit S1 and the DC high voltage generation circuit S3 will be described. First input conductor 15 and second input conductor 16 of inverter circuit S1
From a commercial AC power supply (not shown)
Phase) commercial AC voltage (power) is supplied. The effective value of the commercial AC voltage is, for example, 100 V or 200 V, and the frequency is 50 Hz or 60 Hz.

The AC voltage or AC power supplied to both input conductors 15 and 16 is rectified by a rectifier circuit 17 composed of four diodes and output to a first output conductor 18 and a second output conductor 19. The DC voltage output to both output conductors 18 and 19 is supplied to a smoothing reactor 20 provided on the first output conductor 18, a branch P ₅ of the first output conductor 18, and a branch P ₆ of the second output conductor 19. Connecting wire 2 connecting to
After being smoothed by the smoothing capacitor 22 provided in the first unit 1, it is converted into a high-frequency rectangular-wave AC voltage by the inverter 28 and output to the first low-voltage conductor 29 and the second low-voltage conductor 30. The inverter 28 includes an inductance 23, two thyristors 24 and 25, two diodes 26 and 27, and the like. This rectangular wave AC voltage is a voltage having a voltage waveform in which a rectangular wave on the positive side and a rectangular wave on the negative side alternate alternately. The frequency is very high (for example, several KHz), but the voltage value is commercial. The voltage value of the AC power is not so different (approximately 100 to 200 V on the plus side and the minus side, respectively).

The DC high voltage generating circuit S3 is provided with a pulse transformer 31. A rectangular wave AC voltage is input to the pulse transformer 31 through the low voltage conducting wires 29 and 30. Then, the pulse transformer 31 boosts (voltage converts) the rectangular wave AC voltage to generate an AC high-frequency high voltage (for example, several tens of KV), and outputs the first high-voltage conductor 32 and the second high-voltage conductor 3.
3 and output. The high-frequency high voltage is not a rectangular wave voltage but an alternating voltage that changes in a curved shape (for example, a sine wave). Further, a full-wave rectifier 34 is provided in the DC high-voltage generation circuit S3, and a high-frequency high voltage is input to the full-wave rectifier 34. Then, the full-wave rectifier 34 performs full-wave rectification on the high-frequency AC high voltage to generate a positive DC high voltage, and outputs this to the positive conductor 4 and the negative conductor 5 of the impulse circuit S4. This DC high voltage is a pulsating DC voltage with a duty. Note that the DC high voltage in the conventional plasma processing apparatus is generally a substantially smooth DC.

As described above, the plasma processing apparatus including the inverter circuit S1, the pulse voltage generation circuit S2 (the DC high voltage generation circuit S3 and the inverter circuit S4), and the plasma processing unit S5, or the plasma processing method using the same. According to the pulse transformer 31, the inverter circuit S1
Since the high-frequency rectangular wave AC voltage generated by the pulse transformer 31 is input, the pulse transformer 31 is significantly reduced in size or capacity. Therefore, the size of the plasma processing apparatus is reduced, and the manufacturing cost is reduced.

The high DC voltage input from the full-wave rectifier circuit 34 to the impulse circuit S4 is DC but pulsating (not a smooth DC), so that power loss (heat generation) at the protection resistor 6 is generated. Loss) is reduced and the impulse circuit S
Fourth, the energy efficiency of the plasma processing apparatus is increased, and the operating cost is reduced. Thus, in this plasma processing apparatus, the apparatus for supplying the pulse voltage to the plasma processing section S5, that is, the inverter circuit S1 and the pulse voltage generation circuit S2 are, for example, 1.2 m in width, 1.5 m in depth, and 2.5 m in height. It can be reduced to about 0 m, and it is expected that the manufacturing cost can be reduced to about 1/2 of the conventional case.

An example of the specific specifications of such a plasma processing apparatus is shown below. (Plasma processing unit) Maximum pulse voltage: 50 KV Pulse frequency: 800 pps Processing load: Discharge length 5.4 m, discharge electrode interval 2 cm (Inverter circuit) Power supply specifications: Power supply capacity 4 KVA, input voltage 200 V, frequency 50/60 Hz Output characteristics: voltage 400V, frequency 1KHz, square wave Type: Capacitive load compatible type

(Pulse transformer) Input characteristics: Voltage 400 V (peak to peak), frequency 1 KH
z Output characteristics: Voltage 40KV (peak to peak) Voltage magnification: 100 times Power supply capacity: 40KVA Format: Low impedance type (impulse circuit) Protection resistance: 12KΩ, 160W, (2S) Inductance: 0.4mH Charge / discharge capacity: Cd 0 .6nF (6S3P) 2nF (4
0 KVdc withstand voltage) Gap switch: spherical electrode φ80 mm, 2 electrodes (trigger electrode φ8 mm) Blower: voltage 100 V, air volume 16 m ³ / sec, power consumption 1
KW

FIGS. 2 and 3 show the waveforms of the pulse voltages actually generated by the impulse circuit S4 in the plasma processing apparatus having the above specifications. FIG. 2 shows one pulse in FIG. 3 enlarged in the time axis direction (horizontal axis direction). As is clear from FIGS. 2 and 3,
In this plasma processing apparatus, the peak value (peak value) of the pulse voltage is approximately 50 KV, which is sufficient for generating plasma.

Table 1 shows various electrical characteristics such as pulse voltage output of the plasma processing apparatus according to the present invention (the present case 1 and the present case 2) and the conventional plasma processing apparatus using the impulse circuit (conventional example). The result of the measurement is shown. Table 1 Comparison of various electrical characteristics

As apparent from Table 1, in the conventional example, the peak value (maximum voltage) is 51 KV and the pulse frequency is 660 p.
Producing a pulse voltage of ps requires 2.7 KW of input power. On the other hand, in the first case, even if the discharge length (discharge generation length) is 1.0 m, a pulse voltage better than the conventional example is obtained with the input power of 1.9 KW. Therefore, it can be seen that the plasma processing apparatus according to the present invention has higher output and extremely higher energy efficiency than conventional plasma processing apparatuses of this type. Further, in the second case, the discharge length is as large as 5.4 m, but the input power is 2.9 KW, which is only 1.07 times the input power of the conventional example.

The reason is as follows. That is, in the conventional plasma processing apparatus, since the charge / discharge capacitor is charged by the smooth DC, the power loss (heat generation) is continuously increased in proportion to the product of the square of the current flowing through the protection resistor and the resistance value (I ² R). Loss). On the other hand, in the plasma processing apparatus according to the present invention, the output waveform (secondary waveform) of the pulse transformer generated from the rectangular wave AC voltage is used.
Is a substantially sine wave with a pause. Therefore, heat is not generated by the duty (the ratio of the voltage application time to the pause time) as compared with the conventional smooth DC charging. Therefore, in the plasma processing apparatus according to the present invention, power loss (heat loss) at the protection resistor of the impulse circuit is reduced,
It is assumed that the energy efficiency of the impulse circuit or the plasma processing apparatus is high.

As described above, according to the present invention, the DC high-voltage generating circuit can be reduced in size or capacity, and the power loss (heat loss) of the protection resistor of the impulse circuit can be reduced. In addition, it is possible to provide a compact, small-sized plasma processing apparatus with high energy efficiency or a plasma processing method using the same.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a plasma processing apparatus according to the present invention.

FIG. 2 is a graph showing a change characteristic with time of a pulse voltage generated by an impulse circuit of the plasma processing apparatus according to the present invention.

FIG. 3 is a graph showing a change characteristic with respect to time of a pulse voltage generated by an impulse circuit of the plasma processing apparatus according to the present invention.

FIG. 4 is a circuit diagram showing a configuration of a conventional plasma processing apparatus.

[Explanation of symbols]

S1: inverter circuit, S2: pulse voltage generation circuit, S
3: DC high voltage generation circuit, S4: impulse circuit, S5
... plasma treatment, branches of the P 1 _{to P} 6 _... conductor, 1 ... discharge electrode, 2 ... counter electrode, 3 ... plasma, 4 ... positive side main conductor, 5 ... negative side main conductor, 6 ... protective resistor, 7
.. 1st connection lead, 8 ... inductance coil, 9 ... gap switch, 9a ... ball electrode, 9b ... ball electrode, 10 ... charge / discharge capacitor, 11 ... second connection lead, 12 ... load resistance, 15 ... first input lead , 16 ... second input lead, 17 ...
Rectifier circuit, 18 first output conductor, 19 second output conductor,
Reference Signs List 20: smoothing reactor, 21: connecting conductor, 22: smoothing capacitor, 23: inductance coil, 24: thyristor, 25: thyristor, 26: diode, 27: diode, 28: inverter, 29: first low-voltage conductor, 3
0 ... second low voltage conductor, 31 ... pulse transformer, 32 ... first
High-voltage conductor, 33: second high-voltage conductor, 34: full-wave rectifier.

Claims (7)

[Claims] 1. A surface modification treatment by applying a pulse voltage between a discharge electrode and a counter electrode facing the discharge electrode to generate plasma by corona discharge, and irradiating an object to be processed with the plasma. A plasma processing apparatus configured to apply a high-frequency voltage having a frequency higher than the commercial AC voltage from a single-phase or three-phase commercial AC voltage; and a high-frequency voltage generated by the inverter circuit. A pulse transformer that boosts the voltage to generate a high-frequency high voltage, a full-wave rectifier circuit that generates a DC high voltage by full-wave rectifying the high-frequency high voltage generated by the pulse transformer, and a full-wave rectifier circuit that generates the high-frequency high voltage An impulse circuit for generating a pulse voltage from a DC high voltage and applying the pulse voltage between a discharge electrode and a counter electrode is provided. 2. The plasma processing apparatus according to claim 1, wherein the high-frequency voltage generated by the inverter circuit is a rectangular wave AC voltage. 3. The impulse circuit according to claim 1, wherein the impulse circuit substantially includes a protection resistor, an inductance coil, a charge / discharge capacitor, a gap switch, and a load resistor. Plasma processing equipment. 4. A pulse voltage generated by the impulse circuit has a peak value of 50 to 100 KV, a pulse width of 0.5 to 20 μsec, and a pulse frequency of 95 to 100 μsec.
The plasma processing apparatus according to any one of claims 1 to 3, wherein the electric field strength between both electrodes is set to 4 to 150 KV / cm while being set to 3000 pps. 5. A plasma is generated by corona discharge by applying a pulse voltage between a discharge electrode and a counter electrode facing each other, and the object is irradiated with the plasma to perform a surface modification treatment. A plasma processing method, wherein a high-frequency voltage having a frequency higher than the commercial AC voltage is generated from a single-phase or three-phase commercial AC voltage using an inverter circuit, and the high-frequency voltage is generated by the inverter circuit using a pulse transformer. The high-frequency voltage is boosted to generate a high-frequency high voltage, and using a full-wave rectifier circuit, the high-frequency high voltage generated by the pulse transformer is full-wave rectified to generate a DC high voltage. A plasma processing method, wherein a pulse voltage is generated from a DC high voltage generated by a full-wave rectifier circuit and applied between a discharge electrode and a counter electrode. 6. The high frequency voltage generated by using the inverter circuit is a rectangular wave AC voltage.
4. The plasma processing method according to 1. 7. The pulse generating circuit according to claim 1, wherein the pulse voltage has a peak value of 50 to 100 KV and a pulse width of 0.5 to 2 kV.
Set to 0 μsec and set the pulse frequency to 95 to 3000 pp.
s while the electric field strength between both electrodes is 4 to 150K.
7. The plasma processing method according to claim 5, wherein V / cm is set.