JP2007012489A - Ion generating element and ion generating device equipped with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion generating element in which a discharge starting voltage does not rise and an ion is generated stably even if the tip of the electrode is damaged, and an ion generating device. <P>SOLUTION: The ion generating element comprises a dielectric 3 and a discharge electrode 4 and a guiding electrode 2 opposed to each other through the dielectric 3. A linear electrode 4a is formed at the discharge electrode 4, and the linear electrode 4a is arranged so as to be overlapped with the guiding electrode 2 when the guiding electrode 2 is viewed from the discharge electrode 4. It is preferable that the line width of the linear electrode 4a is 20-100 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ion generation element, an ion generation element, and an ion generation apparatus including the ion generation element, and more particularly to an ion generation element using creeping discharge and an ion generation apparatus including the ion generation element.

Conventionally, a discharge body using creeping discharge has been used as an ion source when charging or neutralizing an object. It has also been reported that positive and negative ions can inactivate airborne bacteria, molds, and the like. For this reason, the ion generating element has come to be mounted on an air cleaner or an air conditioner. As such an ion generating element, an ion generating element using a ceramic mainly composed of alumina as a dielectric for holding an electrode has been devised. In Patent Document 1, a triangular or rectangular electric field concentration portion is provided to start discharge. Discharge bodies with reduced voltage variations have been devised.
JP-A-2-164377

  In the electric field device described in Patent Document 1, a triangular portion is provided on the discharge electrode to cause strong electric field concentration. However, the triangular tip portion is sputtered by ions generated during discharge, and the tip of the electrode is rounded. May end up. When the tip of the electrode is rounded, there is a problem that strong electric field concentration cannot be caused, the discharge start voltage increases, the amount of ion generation becomes unstable, and the power consumption of the ion generator increases.

  Therefore, an object of the present invention is to provide an ion generating element and an ion generating apparatus that generate ions stably without increasing the discharge start voltage.

  An ion generating element according to the present invention includes a dielectric, and a discharge electrode and an induction electrode facing each other with the dielectric interposed therebetween, and a linear electrode portion is formed on the discharge electrode.

  According to the above configuration, the electric field concentrates on the tip of the linear electrode portion, but the tip shape of the linear electrode portion remains linear even if the tip of the linear electrode portion is consumed by sputtering or the like. Since it does not change, ions can be stably generated without increasing the discharge start voltage. Moreover, when the ion generating element which concerns on this invention is mounted in an ion generator, the increase in the power consumption of an ion generator can be prevented.

  As the discharge electrode, a linear electrode portion may be disposed directly from the electrode contact. However, in order to stably apply a voltage to the linear electrode portion, a gap between the electrode contact and the linear electrode portion may be provided. A conductive part to be connected may be provided so that the linear electrode part protrudes from the conductive part. By setting the conductive portion to a sufficient line width compared to the linear electrode portion, it is possible to stably apply a voltage to the linear electrode portion. Moreover, the amount of ion generation can be increased by forming a plurality of linear electrode portions on the discharge electrode.

  The linear electrode portion is preferably arranged so as to overlap with the induction electrode when the induction electrode is viewed from the discharge electrode, whereby ions can be stably generated from the tip of the linear electrode portion. The linear electrode portion may be arranged so that at least the tip portion overlaps with the induction electrode. However, in consideration of the consumption of the linear electrode portion, the entire linear electrode portion is arranged so as to overlap the induction electrode. Is preferred.

  The linear electrode portion may be linear, but if it is formed so as to have a constant line width in all portions, a constant discharge start voltage can be more stably maintained. In order to increase the electric field concentration, the line width of the linear electrode portion is preferably 100 μm or less. Further, when the line width is narrowed, the wear of the linear electrode portion is increased, and considering this, the line width is preferably in the range of several μm to 100 μm, and more preferably 20 μm to 100 μm.

  Further, in order to generate ions using the ion generating element according to the present invention, the ion generating element and an ion provided with voltage applying means for applying a voltage between the discharge electrode and the induction electrode of the ion generating element. What is necessary is just to use a generator, and can obtain the above-mentioned effect by this.

  As described above, according to the present invention, since the linear electrode portion is formed on the discharge electrode, the electric field at the electrode tip does not weaken even if the tip of the electrode is scraped by sputtering or the like. Therefore, ions can be stably generated, and an increase in power consumption of the ion generator can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view of an ion generating element and an ion generating apparatus including the same according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 1 to 2, an ion generating element 10 according to the present invention includes a flat insulating substrate 1, an induction electrode 2 formed on the substrate 1, and a dielectric covering the surface of the induction electrode 2. It comprises a body 3 and a discharge electrode 4 formed on the surface of the dielectric 3. That is, the discharge electrode 4 is disposed on the front surface side of the dielectric 3, and the induction electrode 2 is disposed on the back surface side of the dielectric 3, so that the induction electrode 2 and the discharge electrode 4 face each other through the dielectric 3. Is arranged.

  The discharge electrode 4 includes a discharge electrode contact 7, a linear electrode portion 4a for causing discharge, and a conductive portion 4b connecting the discharge electrode contact 7 to the linear electrode portion 4a. 4b is formed as a belt-like pattern having a sufficient width than the linear electrode portion 4a.

  More specifically, the induction electrode contact 6 and the discharge electrode contact 7 are formed on the substrate 1 with a space therebetween, and the conductive portion 4b is directed from the discharge electrode contact 7 toward the induction electrode contact 6. It is formed in a straight line. The conductive portion 4b is formed with a plurality of linear electrode portions 4a protruding at regular intervals in a direction orthogonal to the conductive portion 4b. The linear electrode portion 4a is formed so as to protrude from both sides of the conductive portion 4b (in a line symmetrical position).

  On the other hand, the induction electrode 2 is formed as a pattern having a sufficient width than the linear electrode portion 4a, like the conductive portion 4b. Then, when the induction electrode 2 is viewed from the discharge electrode 4, the induction electrode 2 is not overlapped with the conductive portion 4 b but is overlapped only with the leading end portion of the linear electrode portion 4 a, with the induction electrode contact 6 as the center. In addition, it is formed in a U shape so as to surround the conductive portion 4b.

  In addition, the induction electrode 2 has a convex portion 2a that protrudes toward the conductive portion 4b at a position facing the linear electrode portion 4a in the U-shaped pattern. The convex portion 2a is formed to be sufficiently wider than the linear electrode portion 4a, so that the linear electrode portion 4a extends from the tip portion to the vicinity of the base portion to the induction electrode 2 (convex portion 2a). It is formed to overlap.

  As described above, the discharge electrode 4 is disposed (superimposed) so that only the linear electrode portion 4 a overlaps the induction electrode 2 when the induction electrode 2 is viewed from the discharge electrode 4. As a result, even when the linear electrode portion 4a is consumed and shortened due to sputtering or the like during discharge, the tip end portion can always maintain a state where it overlaps the induction electrode 2, and stable discharge is possible. .

  As a material of the dielectric 3, for example, an organic substance can be used. As the organic substance constituting the dielectric 3, it is preferable to use a material having excellent corrosion resistance. For example, a resin such as polyimide or glass epoxy may be used as the material of the dielectric 3. In addition, when an inorganic substance is used as the material of the dielectric 3, ceramics such as alumina, magnesia, crystallized glass, forsterite, stearite, mullite, and zirconia can be used as the material of the dielectric 3. Note that it is preferable to use an inorganic material as the dielectric 3 in consideration of resistance to plasma generated when performing discharge for ion generation.

  The material constituting the induction electrode 2 and the discharge electrode 4 can be used without particular limitation as long as it has conductivity. In addition, as a method for forming the induction electrode 2 and the discharge electrode 4, a known method such as a screen printing method, a plating method, a vapor deposition method, or a sputtering method can be used.

  Further, a protective film 5 that covers the surface of the discharge electrode 4 may be provided for the purpose of protecting the discharge electrode 4 from damage caused by sputtering of ions generated during discharge. The protective film 5 is preferably formed as thin as possible if the thickness of the conductor portion of the discharge electrode 4 is not damaged by the discharge. And as a material which comprises a protective film, if it is a material which has plasma resistance, arbitrary materials (For example, inorganic materials, such as a ceramic, etc.) can be used. For example, a material such as alumina or titanium oxide having excellent plasma resistance can be used as the material constituting the protective film 5.

  Next, the manufacturing method of the ion generating element by this invention is demonstrated. The induction electrode 2 is formed by screen-printing and baking Au paste on the alumina substrate 1 having a thickness of 0.8 mm. Further, the induction electrode contact 6 and the discharge electrode contact 7 are formed on the lower surface of the substrate by screen printing and baking. Thereafter, a crystallized glass paste is screen-printed on the substrate 1 so as to cover the induction electrode 2 and then baked to form the dielectric 3.

  Next, a conductor film is formed on the surface of the dielectric 3 by a method such as screen printing, plating, vapor deposition, or sputtering. As a method for forming the conductor film, an inexpensive screen printing method is desirable. In this embodiment, the conductor film is formed by screen-printing Au paste and firing it.

  And the discharge electrode 4 comprised from the linear electrode part 4a with a width of 100 micrometers or less and the electroconductive part 4b is formed by pattern-forming the said conductor film by the photolithographic method and an etching method. The thickness and length of the linear electrode portion 4a are not particularly limited, but in order to obtain a lifetime of 10,000 hours or longer, the length is 1 mm or more and the thickness is 2 μm or more in consideration of the consumption due to sputtering during discharge. Preferably there is.

  Any material may be used as the material constituting the discharge electrode 4 as long as it has conductivity, but preferably, Au as a main component is excellent in resistance to sputtering by ions as in this embodiment. It is better to use the materials described above. In addition, by using a material mainly composed of Au, wet etching can be performed with an iodine-based etchant, and the discharge electrode 4 including the linear electrode portion 4a having a width of 100 μm or less can be formed at a low cost. it can.

  Then, the protective film 5 is formed so that the discharge electrode 4 may be covered as needed, and the ion generating element 10 by this invention can be manufactured. As a method for forming the protective film 5, a method of printing and baking glass paste, a method of drying and baking after dipping in a solution containing a metal alkoxide, or the like can be used. In the present embodiment, the ion generating element 10 is a device in which the pair of induction electrodes 2 and the discharge electrodes 4 are arranged in a row. However, the present invention is not limited to this, and a plurality of rows can be arranged in a row. In this way, the amount of ion generation can be increased.

  If a voltage application circuit 8 provided separately is connected to the induction electrode contact 6 and the discharge electrode contact 7 in order to apply a voltage between the induction electrode 2 and the discharge electrode 4 of the ion generating element 10, The ion generator according to the invention can be obtained.

  By the way, in order to generate both positive and negative ions from the ion generating element 10, an alternating voltage may be applied between the discharge electrode 4 and the induction electrode 2 by the voltage application circuit 8. This alternating voltage is not limited to a sinusoidal alternating voltage (hereinafter referred to as an AC voltage) generally used for commercial power supplies, but may be a rectangular wave alternating voltage, or other waveform. An alternating voltage may be applied using

  Alternatively, a plurality of ion generating elements 10 may be prepared, and positive ions may be generated from one ion generating element and negative ions may be generated from another ion generating element. When positive ions are generated, a voltage may be applied so that the potential of the discharge electrode 4 is higher than the potential of the induction electrode 2. When negative ions are generated, a voltage may be applied so that the potential of the discharge electrode 4 is lower than the potential of the induction electrode 2. When positive ions and negative ions are generated from different ion generating elements, it is possible to suppress the disappearance of ions on the dielectric surface compared to when an alternating voltage is applied, so that ions are generated efficiently. Furthermore, since the number of discharges is reduced, the amount of by-products such as ozone can be suppressed.

In the above configuration, when the voltage application circuit 8 is operated and a high voltage is applied between the discharge electrode 4 and the induction electrode 2, corona discharge occurs in the vicinity of the discharge electrode 4. Thereby, the air around the discharge electrode 4 is ionized, and positive ions made of, for example, H ⁺ (H ₂ O) _m (m is an arbitrary natural number) and O ₂ ⁻ (H ₂ O) _n (n is an arbitrary number). Negative ions consisting of a natural number), and both these ions are released to the outside of the apparatus.

When these both ions adhere to the surface of airborne bacteria or harmful substances in the air, a chemical reaction occurs to generate hydrogen peroxide (H ₂ O ₂ ) or hydroxyl radical (.OH) as active species. By decomposing these active species, airborne bacteria and viruses can be inactivated and allergens can be inactivated.

  Next, the relationship between the width of the linear portion 4a of the discharge electrode and the electric field strength, which is a feature of the present invention, will be described with reference to the graph of FIG. The graph of FIG. 3 shows the relationship between the width of the linear electrode portion 4a and the electric field strength in the vicinity of the tip of the linear electrode portion 4a (a point 1 μm away from the electrode). The broken line in the graph of FIG. 3 has shown the electric field strength when there is no linear electrode part 4a. The electric field strength in FIG. 3 was calculated by the finite element method when the thickness of the dielectric 3 was 50 μm, the relative dielectric constant was 10, and a potential difference of 1800 V was provided between the induction electrode 2 and the discharge electrode 4.

  The electric field strength increases as the width of the linear electrode portion 4a becomes narrower. However, the electric field strength becomes remarkably strong when the line width is 100 μm or less. It was found that an electric field strength stronger than 1% can be obtained.

  That is, by setting the width of the linear electrode portion 4a to 100 μm or less, it is possible to maintain a strong electric field strength even if the tip of the linear electrode portion 4a is damaged.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The top view of the ion generator which shows embodiment of this invention Cross-sectional schematic diagram along line AA in FIG. The figure which shows the relationship between the width | variety of the linear electrode part of FIG. 1, and the electric field strength of the front-end | tip vicinity of a linear electrode part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Induction electrode 2a Convex part 3 Dielectric 4 Discharge electrode 4a Linear electrode part 4b Conductive part 5 Protective film 6 Induction electrode contact 7 Discharge electrode contact 8 Voltage application circuit 10 Ion generating element

Claims (8)

An ion generating element comprising: a dielectric, and a discharge electrode and an induction electrode that are opposed to each other via the dielectric, wherein a linear electrode portion is formed on the discharge electrode. The ion generation element according to claim 1, wherein the discharge electrode includes a discharge electrode contact and a conductive portion connecting the discharge electrode contact and the linear electrode portion. The ion generating element according to claim 1, wherein a plurality of linear electrode portions are formed on the discharge electrode. The ion generating element according to claim 1, wherein the linear electrode portion is disposed so as to overlap the induction electrode when the induction electrode is viewed from the discharge electrode. The ion generating element according to claim 1, wherein the linear electrode portion is formed to have a constant line width. The ion generating element according to claim 1, wherein a line width of the linear electrode portion is 100 μm or less. The ion generating element according to claim 1, wherein Au is used as the discharge electrode. The ion generating element according to claim 1, and voltage applying means for applying a voltage to at least one of the discharge electrode and the induction electrode of the ion generating element. Ion generator.

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