JP4397662B2 - Oxygen negative ion generator - Google Patents

Description

  The present invention relates to an oxygen negative ion generator that generates oxygen negative ions. The oxygen negative ion generator according to the present invention is applied to, for example, an oxidation process of a magnetic device, an oxidation process of semiconductor manufacturing, resist stripping, an oxidation process of a transparent conductive film for a display device, or sterilization in the chemical field. be able to.

In recent years, in a state where an oxygen negative ion emitting portion made of a solid electrolyte with a conductive electrode attached in a vacuum is heated, oxygen gas is introduced and the electrode has a negative (negative potential) voltage with respect to the ground potential. Has been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3), in which oxygen negative ions (O ⁻ ) are generated from the oxygen negative ion emitter. .)

  Further, as another example of the heating means for heating the oxygen negative ion emission part in Patent Document 1, an oxygen negative ion generator as shown in FIG. 2 has been proposed.

An oxygen negative ion generating apparatus 100 shown in FIG. 2 includes an oxygen negative ion generating member 1 made of a cylindrical solid electrolyte having a disk-shaped oxygen negative ion emitting portion 1a that seals the tip side. An end flange 1 b is held in close contact with the distal end opening of the ion generation container 2 via an O-ring 3. As the oxygen minus ion generator member 1, and using calcium aluminate as the oxygen minus ion generator 100, a solid electrolyte _{((CaO) 12 (Al 2} O 3) 7). The oxygen negative ion generating member 1 having an oxygen negative ion emitting portion 1a made of a solid electrolyte has a large number of fine holes, and can fill and permeate oxygen negative ions.

  An electrode 4 made of a conductive metal is attached to the back side of the oxygen negative ion emitting portion 1a (inside the ion generating container 2) by applying and baking a liquid paste or by vacuum deposition. The electrode 4 is made of a conductive material such as platinum, gold, or lanthanum manganate having a thickness of 0.5 μm to 1 μm, and has a large number of fine holes. A DC power supply 6 is connected to the electrode 4 through a conducting wire 5, and a negative (minus) DC voltage is applied from the DC power supply 6. In addition, a disk-shaped extraction electrode 7 having a large number of pores with a gap of several mm is supported by a support member 8 in front of the opposite side (surface side) of the oxygen negative ion emission part 1a. Installed.

  Since the extraction electrode 7 is grounded (ground potential), it has a positive (positive) potential with respect to the potential (negative potential) of the electrode 4 of the oxygen negative ion emitting portion 1a. Therefore, negatively charged oxygen negative ions generated in the oxygen negative ion emitting portion 1a are released toward the extraction electrode 7 side. In addition, the space where the outside of the oxygen negative ion generating member 1 and the extraction electrode 7 are installed constitutes a part of the vacuum chamber 21 held in a high vacuum.

  A cylindrical quartz column 9 is provided inside the oxygen negative ion generating member 1 with a gap of several mm from the inner side, and the tip side of the quartz column 9 (oxygen negative ion emitting portion 1a side) is oxygen. It has a gap of several mm from the negative ion emission part 1a. The rear end side of the quartz column 9 is held in close contact with the rear end side opening of the ion generation vessel 2 via an O-ring 10, and the rear end portion of the quartz column 9 is exposed to the outside of the ion generation vessel 2. Yes.

  A halogen lamp 12 connected to a heater power supply 11 is installed near the rear end of the quartz pillar 9, and a reflector 13 is installed around the halogen lamp 12. The reflector 13 is transmitted with infrared light A emitted from the halogen lamp 12 generated by energization from the heater power supply 11 while repeating total reflection on the inner peripheral surface of the quartz column 9, and the back surface of the oxygen negative ion emitting portion 1a. It is formed in a curved shape so as to efficiently enter the surface of the electrode 4 formed in the above.

  An oxygen cylinder 17 is connected to an oxygen gas inlet 2a provided in the ion generation vessel 2 through a gas introduction pipe 16 having a valve 14a, a gas flow rate regulator 15, and a valve 14b. An exhaust pump 20 is connected to an exhaust port 2 b provided in the ion generating container 2 via an exhaust pipe 19 having a valve 18.

  The oxygen negative ion generator 100 in the conventional example is configured as described above, and when generating oxygen negative ions, the halogen lamp 12 is heated by energization from the heater power supply 11. Then, the infrared light A radiated from the halogen lamp 12 due to heat generation is reflected by the inner surface of the reflector 13 and transmitted while repeating total reflection on the inner peripheral surface of the quartz column 9, and is transmitted to the back surface of the oxygen negative ion emitting portion 1a. It efficiently enters the formed electrode 4 and heats the oxygen negative ion emitting portion 1 a together with the electrode 4. By this heating, the back side of the oxygen negative ion emitting portion 1a becomes about 800 ° C.

At this time, from the state in which the exhaust pump 20 is driven and the inside of the ion generation container 2 is evacuated, the flow rate is adjusted from the oxygen cylinder 17 by the gas flow rate controller 15, and then the oxygen generation container 2 is oxygenated through the oxygen gas inlet 1 a. The gas is introduced at a flow rate of about 100 to 1000 sccm, and the inside of the ion generation container 2 is set to about 1.3 × 10 ² Pa.

Under the above conditions, the oxygen gas introduced into the ion generating container 2 is filled into the oxygen negative ion emitting portion 1a made of calcium aluminate as the solid electrolyte through the electrode 4. In the oxygen negative ion emission part 1a, most of the oxygen exists as O ²⁻ , but when the oxygen negative ion emission part 1a is heated, oxygen filled in the oxygen negative ion emission part 1a ( One electron is added to O ₂ ) and converted from O ²⁻ to O ⁻ .

In this state, by applying a negative (minus) DC voltage from the DC power source 6 to the electrode 4 via the conductive wire 5, an electric field is formed in the oxygen negative ion emitting portion 1a, and oxygen negative ions (O ⁻ ) are generated. It moves by ion conduction from the back side to the surface (extraction electrode 7 side). Then, the oxygen negative ions (O ⁻ ) that have moved to the surface of the oxygen negative ion emitter 1a are released into the vacuum toward the front (extraction electrode 7 side), and pass through a large number of pores provided in the extraction electrode 7. And released into the vacuum chamber 21.

The oxygen negative ions (O ⁻ ) thus taken out are oxidized in the magnetic device, or in the semiconductor manufacturing oxidation process or resist stripping, or in the oxidation process for the transparent conductive film for the display device, or sterilized in the chemical field. Etc. can be used.
Japanese Patent Application No. 2002-171631 (FIG. 1) JP-A-6-244841 International Publication No. WO 03/050037

By the way, in the conventional oxygen negative ion generator 100 shown in FIG. 2, as described above, the oxygen negative ion generating member 1 including the oxygen negative ion emitting portion 1a is entirely composed of calcium aluminate ((CaO) as a solid electrolyte. ₁₂ (Al ₂ O ₃ ) ₇ ).

  The strength of this calcium aluminate itself is not so great. That is, the values of fracture, cutting stress and the like are almost similar to those of general glass, and may be broken not only by external stress but also by strain or thermal stress caused by heating. For this reason, conventionally, the shape of the oxygen negative ion release portion 1a of the oxygen negative ion generating member 1 made of calcium aluminate (rounded corners, thickened, etc.) and heating method (local temperature difference is However, the reliability is still insufficient for impact and handling from the outside.

  Further, in the conventional oxygen negative ion generator 100 described above, the oxygen negative ion generating member 1 has a cylindrical total length of about 100 mm and the oxygen negative ion emitting portion 1a has a diameter of about 23 mm. In order to further increase the size of the generating member 1, there is a limit in maintaining the strength only by improving the shape and heating method as described above.

  Further, when the oxygen negative ion generating member 1 is formed of calcium aluminate as a solid electrolyte as in the conventional oxygen negative ion generator 100 described above, the optimum temperature for releasing oxygen negative ions is 800 ° C. to Although the temperature is about 900 ° C., when the vicinity of the tip having the oxygen negative ion emitting portion 1a is heated to this temperature, the back side, which is the oxygen supply side, reaches a temperature of about 800 ° C.

  For this reason, the oxygen minus ion generating member 1 is more dominant in releasing oxygen than taking in oxygen, and oxygen minus released to the surface side (extraction electrode 7 side) of the oxygen minus ion emitting portion 1a. The current value corresponding to the ions is limited to about 1 μA by limiting the supply rate of oxygen minus ions that are taken in and conducted from the back side (the side opposite to the extraction electrode 7 side) of the oxygen minus ion emitting portion 1a, and is about 1 μA. There was little release of oxygen negative ions from the surface of the negative ion emission part 1a.

  Therefore, the present invention can ensure sufficient strength of an oxygen negative ion generating member made of a solid electrolyte, and ensure strength that does not cause damage to the oxygen negative ion generating member even when the oxygen negative ion generating member is enlarged. It is an object of the present invention to provide an oxygen negative ion generator capable of performing the following.

  It is another object of the present invention to provide an oxygen negative ion generator that can increase the amount of oxygen minus ions released by increasing the amount of oxygen taken into the oxygen negative ion generating member.

To achieve the above object, the present invention provides an oxygen negative ion generating member made of a solid electrolyte and a conductive material having a number of micropores formed on the back surface of the oxygen negative ion generating member opposite to the oxygen negative ion emitting side surface. First electrode, a conductive second electrode having a large number of pores provided in front of the oxygen negative ion emission side surface of the oxygen negative ion generating member, and heating means for heating the oxygen negative ion generating member And oxygen gas introducing means for introducing oxygen gas to the back side of the oxygen negative ion generating member in the vacuum state where the first electrode is provided, and applying a negative polarity voltage to the first electrode The second electrode side is set to a higher potential on the positive potential side than the first electrode side, and the oxygen negative ion generating member is heated to a predetermined temperature by the heating means. In addition, oxygen negative ions are generated in the oxygen negative ion generating member by introducing oxygen gas by the oxygen gas introducing means to the back side of the vacuum oxygen negative ion generating member provided with the first electrode. The oxygen negative ion generator is configured to discharge the generated oxygen negative ions from the oxygen negative ion emission side surface of the oxygen negative ion generation member through the pores of the second electrode and to the front of the second electrode. Then, the oxygen negative ion generating member is coated on a base made of a solid electrolyte stronger than calcium aluminate and a thin layer made of a solid electrolyte that generates oxygen negative ions on the surface of the base on the second electrode side. cylindrical shape to form the other end one end opened is sealed with a disc-shaped oxygen negative ion emitting unit And it is,
It is characterized in that the second electrode on the front surface side of the oxygen negative ions of the oxygen minus ion emitting unit is released is provided.

  Further, the substrate is characterized in that it is zirconia or yttria stable zirconia.

  In addition, the first electrode is formed on the entire back surface of the base on which the oxygen negative ion generating member is formed, which is opposite to the surface coated with the thin layer.

  According to the present invention, the oxygen negative ion generating member is formed on a base made of a solid electrolyte stronger than calcium aluminate, and is made of a solid electrolyte that generates oxygen negative ions on the surface of the base on the second electrode side. By forming a thin layer, it is possible to increase the strength of the oxygen negative ion generating member along with the release of oxygen negative ions, and even when the oxygen negative ion generating member is enlarged, destruction or the like occurs. It is possible to ensure the strength without any problem.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

  FIG. 1 is a schematic cross-sectional view showing an oxygen negative ion generator according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as the conventional oxygen negative ion generator shown in FIG. 2, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 1, the oxygen negative ion generator 30 according to the embodiment of the present invention has an oxygen negative ion on the outer periphery on the tip side where the oxygen negative ion emitting portion 1 a of the cylindrical oxygen negative ion generating member 1 is located. A ring-shaped halogen lamp (hereinafter referred to as a circle lamp) 22 is provided with a gap of several mm from the outer peripheral surface of the generating member 1. Reflectors 23 are provided around the side surface and the back surface of the circle lamp 22, and the circle lamp 22 and the reflector 23 are supported by the ion generation container 2 by a support member 24.

Then, in the oxygen minus ion generating apparatus 30 according to the embodiment of the present invention, the substrate 1c for forming a cylindrical oxygen minus ion generator member 1 is formed of zirconia having strength as a solid electrolyte (ZrO ₂₎ In addition, the entire surface of the substrate 1c (on the side of the circle lamp 22) excluding the flange 1b is made of calcium aluminate ((CaO) ₁₂ (Al ₂ O ₃ ) ₇ ) that generates oxygen negative ions as a solid electrolyte. A thin layer 25 is coated. The thin layer 25 made of calcium aluminate ((CaO) ₁₂ (Al ₂ O ₃ ) ₇ ) can be coated by, for example, a known plasma spraying method. The oxygen negative ion emitting member 1 has a thickness of 3 mm, and the other portions have a thickness of 2 mm. The thin layer 25 has a thickness of about 100 μm.

  Further, an electrode 4 made of a conductive metal is applied to the entire inner surface of the substrate 1c (the back surface opposite to the surface on the extraction electrode 7 side) by applying a liquid paste or by vapor deposition in a vacuum. A film is formed. The electrode 4 is made of a conductive material such as platinum, gold, or lanthanum manganate having a thickness of 0.5 μm to 1 μm, and has a large number of fine holes. A DC power supply 6 is connected to the electrode 4 through a conducting wire 5, and a negative (minus) DC voltage is applied from the DC power supply 6.

  The oxygen negative ion generating apparatus 30 according to the present embodiment having the above-described configuration is the total length of the oxygen negative ion generating member 1 (the length between the oxygen negative ion emitting portion 1a and the base end 1b): 100 mm, oxygen negative Thickness of ion emission part 1a: 3 mm, diameter of oxygen negative ion emission part 1a: 23 mm, diameter of lamp tube of circle lamp 22: 10 mm, output of circle lamp 22: 160 W to 300 W, inner circumferential surface of circle lamp 22 and oxygen The gap between the surfaces of the negative ion generating member 1 is set to 3 mm, and the applied voltage to the electrode 4 is set to −100V.

  When oxygen negative ions are generated by the oxygen negative ion generator 30 in the present embodiment, the circle lamp 22 is heated by energization from a lamp power source (not shown). Infrared light radiated from the circle lamp 22 by the heat generated by the circle lamp 22 is reflected by the reflector 23 and heats the vicinity of the tip of the oxygen minus ion generating member 1 having the oxygen minus ion emitting portion 1a.

  Due to the heat generated by the circle lamp 22 provided outside the oxygen negative ion generating member 1, the entire surface side of the oxygen negative ion emitting portion 1a is effectively and uniformly heated by radiation. Due to heating by the outer circle lamp 22, the surface side of the oxygen-negative ion emission part 1a becomes about 800 ° C. where oxygen-negative ions are generated.

At this time, from the state where the exhaust pump 20 is driven and the inside of the ion generating container 2 is evacuated to about 1.3 × 10 ⁻³ Pa, the oxygen gas introduction port is adjusted while adjusting the flow rate from the oxygen cylinder 16 with the gas flow rate regulator 15. Oxygen gas is introduced into the ion generation container 2 through 1a at a flow rate of about 100 to 1000 sccm, and the inside of the ion generation container 2 is set to about 1.3 × 10 ² Pa.

In this state, by applying a negative (minus) DC voltage (−100 V) from the DC power source 6 to the electrode 4 through the conductive wire 5, an electric field is formed in the oxygen negative ion emitter 1 a, and oxygen negative ions (O ⁻ ) moves by ion conduction from the back side to the surface (extraction electrode 7 side).

  At this time, in the present embodiment, the electrode 4 made of a conductive metal is formed on the entire inner surface of the substrate 1c forming the oxygen negative ion generating member 1 (the back surface opposite to the surface on the extraction electrode 7 side). As a result, a temperature gradient is generated between the oxygen negative ion emitting portion 1a and the brim portion 1b (the lower side of the brim portion 1b is lower), which is optimal for taking oxygen into the oxygen negative ion emitting portion 1a side. A temperature region (approximately 500 ° C. to 600 ° C.) exists, and oxygen is efficiently taken into the oxygen negative ion generating member 1.

The oxygen negative ions migrate to the surface of the oxygen minus ion emitting portion 1a (O ^-) are emitted into the vacuum forward (extraction electrode 7 side), through a number of pores provided in the lead-out electrode 7 And released into the vacuum chamber 21.

  Then, when the amount of released oxygen minus ions generated by the oxygen minus ion generator 30 according to this embodiment having the above-described configuration is measured by a current that increases or decreases according to the amount of released oxygen minus ions, a value of about 20 μA is obtained. As a result, it was confirmed that a large number of oxygen negative ions were stably released from the surface of the oxygen negative ion emitting portion 1a.

Thus, in the oxygen negative ion generating apparatus 30 according to the present embodiment, the base 1c forming the oxygen negative ion generating member 1 including the oxygen negative ion emitting portion 1a is used as a strong zirconia (ZrO ₂₎ as a solid electrolyte. ), And a thin layer 25 made of calcium aluminate ((CaO) ₁₂ (Al ₂ O ₃ ) ₇ ) that generates oxygen negative ions as a solid electrolyte is coated on the surface thereof. As the oxygen negative ion generating member 1 is released, the strength of the oxygen negative ion generating member 1 can be increased, and even when the oxygen negative ion generating member 1 is increased in size, it is possible to ensure strength that does not cause destruction.

  Further, in the oxygen negative ion generator 30 according to the present embodiment, the electrode 4 made of a conductive metal is formed on the entire inner surface of the base 1c forming the oxygen negative ion generating member 1, whereby oxygen is generated. Since an optimal temperature range (about 500 ° C. to 600 ° C.) can be obtained for taking in the oxygen negative ion emitting portion 1a, the area for taking in oxygen increases, and a large number of oxygen negative ions can be stably released. it can.

In the above-described embodiment, the base 1c that forms the oxygen negative ion generating member 1 including the oxygen negative ion emitting portion 1a is formed of strong zirconia (ZrO ₂ ) as a solid electrolyte. However, the present invention is not limited to this. In addition, for example, yttria stable zirconia (Y ₂ O ₃ stabilized ZrO ₂ ) or the like can be used.

The schematic sectional drawing which shows the oxygen negative ion generator which concerns on embodiment of this invention. The schematic sectional drawing which shows the oxygen negative ion generator in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oxygen negative ion generating member 1a Oxygen negative ion discharge | release part 1b Head part 1c Base | substrate 2 Ion generation container 4 Electrode (1st electrode)
6 DC power supply 7 Lead electrode (second electrode)
22 Circle lamp (heating means)
25 Thin layer 30 Oxygen negative ion generator

Claims (3)

An oxygen negative ion generating member made of a solid electrolyte, a conductive first electrode having a large number of micropores formed on the back surface of the oxygen negative ion generating member opposite to the oxygen negative ion emission side surface, and the oxygen negative ion A conductive second electrode having a large number of pores provided in front of the oxygen negative ion emission side surface of the generating member, heating means for heating the oxygen negative ion generating member, and generation of the oxygen negative ions in a vacuum state Oxygen gas introducing means for introducing oxygen gas to the back side of the member on which the first electrode is provided, and a negative polarity voltage is applied to the first electrode, and the second electrode side is connected to the first electrode. The oxygen negative ion generating member is heated to a predetermined temperature by the heating means and set to a higher potential side than the positive potential side. By introducing oxygen gas by the oxygen gas introducing means to the back side of the eggplant ion generating member where the first electrode is provided, oxygen negative ions are generated in the oxygen negative ion generating member, and the generated oxygen negative ions are An oxygen negative ion generator that discharges from the oxygen negative ion emission side surface of the oxygen negative ion generation member through the pores of the second electrode and discharges in front of the second electrode,
The oxygen negative ion generating member is coated on a base made of a solid electrolyte stronger than calcium aluminate, and a thin layer made of a solid electrolyte that generates oxygen negative ions is coated on the surface of the base on the second electrode side. Formed in a cylindrical shape with one end opened and the other end sealed with a disk-like oxygen-negative ion emitter,
The second electrode is disposed in front of the surface side from which oxygen negative ions are released from the oxygen negative ion emitting portion,
An oxygen negative ion generator characterized by that. The substrate is zirconia or yttria stable zirconia;
The oxygen negative ion generator according to claim 1. The first electrode is formed on the entire back surface of the base opposite to the surface coated with the thin layer of the oxygen negative ion generating member.
The oxygen negative ion generator according to claim 1 or 2.

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