KR100861559B1 - Atmospheric plasma generating apparatus with the electrode part that has several electrodes on the lower surface of a dielectric coupled to the power applied electrode - Google Patents

Abstract

An atmospheric plasma generating apparatus including an electrode part having several electrodes on a lower surface of a dielectric coupled to a power-applied electrode is provided to improve surface processing performance using atmospheric plasma by boosting a voltage. A first electrode(10) receives a discharge voltage from a power supply unit. A dielectric is attached to the first electrode or is formed to surround the first electrode. A second electrode(20) is attached to a lower surface of the dielectric. The second electrode includes a plurality of electrodes which are arranged in a predetermined interval from each other. An insulating layer for preventing a damage of an electrode is formed to surround the second electrode. An exterior electrode housing includes the first electrode, the dielectric, and the second electrode to surround an electrode structure.

Description

Atmospheric plasma generating apparatus with the electrode part that has several electrodes on the lower surface of a dielectric coupled to the power applied electrode}

1 is a view showing an electrode structure of a conventional atmospheric plasma generator;

2 is a view showing an electrode structure of an atmospheric pressure plasma generating apparatus according to a first embodiment of the present invention;

3 is a view showing that a plasma is generated around a second electrode by applying a voltage to the atmospheric pressure plasma generator of the present invention to generate a discharge;

4 is a view showing an electrode structure of an atmospheric pressure plasma generating apparatus according to a second embodiment of the present invention;

5 is a view showing an electrode structure of an atmospheric pressure plasma generating apparatus according to a third embodiment of the present invention;

6 is an exemplary view of applying the electrode structure of the present invention to the field of air or water purification.

<Description of the symbols for the main parts of the drawings>

1: voltage applied electrode 2: lower electrode

3: dielectric 4: alternating voltage

10: first electrode 20: second electrode

30: dielectric 40: insulator for preventing electrode damage

50: electrode outer housing 60: plasma outlet

70: plasma

The present invention relates to an atmospheric pressure plasma generating apparatus having an opposite electrode structure, and more particularly, an initial discharge voltage and an electrode to which voltages are applied to both surfaces of a dielectric and electrodes arranged to be spaced apart from each other at a predetermined interval to face each other. An atmospheric pressure plasma generator having a counter electrode structure capable of lowering a plasma holding voltage.

In the process of manufacturing a semiconductor device including a display device such as a flat panel display (FPD), a surface treatment process such as cleaning, surface modification, etching is required. As the initial method of surface treatment of the workpiece, a chemical method was mainly used, and surface treatment by chemicals has a problem of generating waste and effluents. The study proceeded in the direction.

Recently, a method that has attracted attention as a physical surface treatment method is a method using plasma, and in the industrial field, the surface treatment process of semiconductors is gradually replaced by a method using plasma gradually in the past chemical surface treatment method.

Plasma refers to a group of charged particles in which a gas is ionized by energy so that ions and electrons are uniformly distributed at about the same density and thus exhibit overall electrical neutrality. When the external energy above the threshold is applied to the gas, the gas is ionized with ions and electrons to form a plasma. When a particle with high energy in the plasma state strikes the surface of a material, the energy is transferred to the surface of the colliding material for surface treatment.

Currently, the process of utilizing plasma in the development of display devices is gradually increasing, and a vacuum plasma generator is mainly used. While the vacuum plasma generator has the advantage of precisely controlling the surface treatment, the cost of the equipment is expensive and time-consuming. Therefore, research is being actively conducted to utilize an atmospheric pressure plasma generator capable of generating plasma without maintaining a vacuum, and even in an industrial field, a vacuum plasma generator is being replaced by an atmospheric pressure plasma generator. Types of atmospheric plasma currently being studied or used include corona discharge, dielectric barrier discharge (DBD), and atmospheric pressure RF capacitive discharge.

1 shows an electrode structure of a conventional atmospheric plasma generator of DBD (dielectric barrier discharge) method. FIG. 1A illustrates a form in which an upper electrode to which power is applied and a dielectric are in close contact with each other, and FIG. 1B encloses an upper electrode 1 'to which power is applied so as to be spaced apart from the upper electrode by a predetermined distance. It is a structure made of a dielectric 3 'of the form. The space between the upper electrode and the dielectric may be filled with distilled water or a liquid dielectric. The present invention is characterized in that a plurality of separate electrodes are formed on the lower surface of the dielectric positioned between the electrode to which the power is applied and the plasma generating region, so that the conventional upper electrode (power supply electrode) and the dielectric are combined in some form. Since it is irrelevant to the problem of having a structure, the present invention will be described below with reference to Fig. 1A only.

As shown in FIG. 1A, the voltage applying electrode 1 and the lower electrode 2 are connected to the AC voltage 4, and the dielectric 3 is provided on the lower surface of the voltage applying electrode 1. It is. In this case, the dielectric 3 may be additionally installed not only on the voltage applying electrode 1 but also on the upper surface of the lower electrode 2. When the discharge voltage is applied between the two electrodes by the alternating voltage 4, the charge is generated. It limits the amount of charge generated and allows charge to spread throughout the electrode.

In the atmospheric pressure plasma generator of the DBD method, since the discharge occurs through the dielectric 3, the electrode is prevented from being damaged.

However, since the discharge must be performed at atmospheric pressure rather than vacuum, a considerably higher voltage must be applied between the two electrodes as compared with the low pressure, thereby causing a problem of high initial discharge voltage and plasma holding voltage.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to lower the initial discharge voltage by arranging electrodes arranged at predetermined intervals on the opposite side of the dielectric to which the voltage is applied, and thus the plasma. The present invention provides an atmospheric pressure plasma generator having an opposite electrode structure capable of lowering a sustain voltage.

Atmospheric pressure plasma generating apparatus of the opposite electrode structure of the present invention for achieving the above object, the first electrode to which the discharge voltage is applied from the power supply means; A dielectric attached to the first electrode or surrounding the first electrode; And a second electrode attached to a lower surface of the dielectric and composed of a plurality of electrodes spaced apart from each other at predetermined intervals. It is configured to include.

Optionally, the electrode layer may further include an insulating layer for preventing damage to the electrode.

The apparatus may further include an electrode outer housing surrounding an electrode structure including the first electrode, the dielectric, and the second electrode, or the insulating layer for preventing damage to the first electrode, the dielectric, the second electrode, and the electrode. It further comprises an electrode outer housing surrounding the electrode structure.

Preferably, the electrode outer housing is characterized in that at least one plasma outlet is formed on one surface facing the second electrode.

Hereinafter, an atmospheric pressure plasma generating apparatus having a counter electrode structure according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing the electrode structure of the atmospheric pressure plasma generating apparatus according to the first embodiment of the present invention.

Fig. 2 (a) is a side view of the atmospheric pressure plasma generator of the counter electrode structure of the present invention as seen from the side.

The atmospheric pressure plasma generator of the counter electrode structure of the present invention is largely composed of the first electrode 10, the second electrode 20, and the dielectric 30. As shown in Fig. 2 (a), the first electrode 10 made of a conductor and the dielectric 30 are disposed adjacent to each other to face each other, and the second electrode 20 made of a conductor is also provided. The dielectric 30 is disposed adjacent to each surface thereof. In this case, the second electrodes 20 made of a plurality of electrodes are disposed apart from each other with a predetermined distance therebetween, and the first electrodes of the dielectric 30 are disposed on opposite sides which are not adjacent to each other, thereby interposing the dielectric 30 between them. The first electrode 10 is formed to face each other. The shape of the cross section of the second electrode 20 generally forms a flat rectangle as shown in FIG. 2 (a), but is not necessarily limited to the shape of the rectangle.

Referring to FIGS. 2B and 2C, an electrode structure including the first electrode 10, the second electrode 20, and the dielectric 30 will be described in more detail as follows. Figure 2 (b) shows a front view of the atmospheric pressure plasma generating apparatus of the counter electrode structure of the present invention, Figure 2 (c) shows a bottom view.

As shown in Fig. 2 (b), the portions represented in white represent the dielectric material 30, which crosses the surface of the dielectric material 30, and the second electrodes 20 are parallel to each other at a predetermined interval in a band shape. It is arranged. These strip-shaped electrodes are connected to each other at the left and right ends. On the other hand, since the first electrode 10 is located on the rear surface of the dielectric 30, the first electrode 10 is not visible from the surface on which the second electrode 20 is disposed. The area of the electrode 10 is shown.

Referring to FIG. 2C, a white layer positioned in the center of the electrode structure represents the dielectric material 30, the first electrode 10 is disposed on the top surface of the dielectric material 30, and the second electrode is formed on the bottom surface of the dielectric material material 30. 20 is disposed. That is, the first electrode 10 and the second electrode 20 have an opposite structure with the dielectric 30 interposed therebetween. The second electrode 20 is one electrode is formed across the entire side of the dielectric 30, referring to the shape of the second electrode 20 shown in Figure 2 (a) the overall shape of the second electrode. Judging from the above, it can be seen that a plurality of electrodes having a shape intersecting the entire side of the dielectric 30 are arranged at regular intervals.

3 is a view showing that plasma is generated between the second electrodes after a voltage is applied to the atmospheric pressure plasma generator of the present invention to generate a discharge.

As shown in FIG. 3, when a voltage is applied between the first electrode 10 and the second electrode 20 to generate a plasma, each second electrode 20 attached to the lower surface of the dielectric 30 is applied. Discharge occurs in the space between the plasma 70 is generated. In order to perform plasma generation more effectively under atmospheric pressure, a reactive gas is injected into a space where a discharge occurs. Here, the dielectric 30 serves to limit the amount of charge discharged and to spread the charge throughout the electrode. When a discharge is generated in the discharge space and the plasma 70 is generated, the surface treatment such as cleaning, surface modification, etc. of the workpiece is performed according to the processing purpose of the workpiece placed under the discharge space.

As described above, when the boundary surface of the electrode is formed in plural like the second electrode 20 shown in FIG. 3, the first electrode is lowered at a lower voltage than when the second electrode is composed of one electrode plate having a single surface. An initial discharge may be caused between the 10 and the second electrode 20, and the voltage required to generate and maintain the plasma may be lowered thereafter.

4 is a view showing the electrode structure of the atmospheric pressure plasma generating apparatus according to the second embodiment of the present invention.

As shown in FIG. 4A, since the second electrode 20 disposed under the dielectric 30 is exposed to the air as it is, when used for a long time compared to the first electrode 10 protected by the dielectric barrier, Damage or abrasion may occur little by little. In addition to the damage caused by the discharge, there is a fear of physical damage caused by external exposure. Therefore, in order to prevent the second electrode 20 from being damaged, the entire dielectric surface on which the plurality of second electrodes 20 are disposed may be surrounded. An insulating layer 40 for preventing electrode damage may be added.

In FIG. 4A, the insulating layer 40 is formed over the entire lower surface of the dielectric. However, as shown in FIG. 4B, only the respective electrodes may be covered.

5 is a view showing the electrode structure of the atmospheric pressure plasma generating apparatus according to a third embodiment of the present invention.

As shown in FIG. 5, an electrode outer housing 50 surrounds the entire atmospheric pressure plasma electrode structure including the first electrode 10, the dielectric 30, and the second electrode 20. In this case, the atmospheric pressure plasma electrode structure surrounded by the electrode outer housing 50 may further include an insulating layer for preventing electrode damage surrounding the dielectric 30 and the second electrode 20.

One or more plasma outlets 60 may be formed on a surface facing the second electrode 20 of the electrode outer housing 50, and the plasma outlets 60 may have various shapes according to the processing purposes of the workpiece such as slits and holes. Can be implemented. In addition, the use range of the plasma generating apparatus can be changed by modifying the shape of the electrode outer housing 50.

When a discharge voltage is applied between the first electrode 10 and the second electrode 20 with the dielectric 30 interposed by the power supply means, a discharge occurs in a space where the second electrode 20 is in contact with each other, thereby generating a plasma. In addition, the plasma is discharged to the workpiece placed on the lower end of the electrode outer housing 50 through the plasma discharge opening 60 to perform cleaning, surface modification, and the like on the workpiece.

Up to now, the embodiment of the present invention has been described by taking the case of surface treatment as an example, but the field of use of plasma is various in addition to the surface treatment field. Currently, the most widely used field is the display field, but the air and water purification fields are also widely used / researched.

6 shows an example in which the electrode structure of the present invention is applied to the field of air or water purification. As shown in FIG. 6, when the electrode structure of the present invention is applied to the upper electrode to generate a plasma, and the contaminated air or waste water passes between the upper and lower electrodes, the contaminated air or waste water reacts with the plasma to remove contaminants. In FIG. 6, the electrode structure of the present invention is shown to be applied only to the upper electrode, but it is of course possible to apply the electrode structure of the present invention to both the upper and lower electrodes as well as to the lower electrode. Since the process of purifying contaminated air or waste water by plasma is well known, detailed descriptions are omitted, and the present invention is only intended to mention that the electrode structure of the present invention can be applied to such a conventional purifier.

Preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art to which the present invention pertains various substitutions, modifications, and without departing from the spirit of the present invention. And changes will be possible, and such substitutions, changes and the like should be regarded as falling within the scope of the following claims.

As described above, according to the atmospheric pressure plasma generating apparatus of the opposite electrode structure according to the present invention, atmospheric pressure plasma generation having an electrode structure in which the electrodes arranged at a predetermined interval on the opposite side of the dielectric with the electrode to which the voltage is applied is arranged Providing the device has the effect of lowering the initial discharge voltage and the plasma holding voltage of the atmospheric pressure plasma.

Therefore, it is possible to apply a higher voltage than the conventional atmospheric plasma generating apparatus, there is an effect to further improve the surface treatment ability using the atmospheric pressure plasma.

Claims (6)

In the plasma generating apparatus, A first electrode to which a discharge voltage is applied from a power supply means; A dielectric attached to the first electrode or surrounding the first electrode; And A second electrode attached to a lower surface of the dielectric and composed of a plurality of electrodes spaced apart from each other at predetermined intervals; Atmospheric pressure plasma generating apparatus of the opposite electrode structure comprising a. The method of claim 1, Atmospheric pressure plasma generator of the opposite electrode structure characterized in that it further comprises an insulating layer for preventing damage to the electrode surrounding the second electrode. The method of claim 1, And an electrode outer housing surrounding the electrode structure including the first electrode, the dielectric, and the second electrode. The method of claim 3, The electrode outer housing is an atmospheric pressure plasma generator of the opposite electrode structure, characterized in that at least one plasma outlet is formed on one surface facing the second electrode. The method of claim 2, And an electrode outer housing surrounding the electrode structure including the first electrode, the dielectric, the second electrode, and the insulating layer for preventing damage to the electrode. The method of claim 5, The electrode outer housing is an atmospheric pressure plasma generator of the opposite electrode structure, characterized in that at least one plasma outlet is formed on one surface facing the second electrode.

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