JP4043141B2 - Method for manufacturing electron emission source and electron emission source - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing an electron emission source that emits electrons, an electron emission source manufactured by the method, and a fluorescent display using the electron emission source.
[0002]
[Prior art]
A field electron emission source that emits electrons by the action of an electric field has many advantages such as energy saving and longer life compared to an electron source that uses thermal energy (thermoelectron emission source). Known materials for field electron emission sources include semiconductors such as silicon, metals such as tungsten and molybdenum, diamond-like carbon (DLC), and the like.
[0003]
The field emission phenomenon is a phenomenon in which, when the applied electric field on the surface of a metal or semiconductor is set to about 10 ⁹ V / m, electrons are emitted into a vacuum even at room temperature through a barrier due to a tunnel effect. Therefore, how much high electric field can be applied from an extraction electrode (hereinafter referred to as a gate electrode) to an emitter formed of an electron emission material that emits electrons determines the extraction current.
[0004]
It is known that the sharper the tip of the emitter, the higher the electric field strength applied to the emitter. For this reason, it is necessary to process the tip of the electron emission portion of the semiconductor or metal into a sharp needle shape. However, it is not easy to process the tip of the semiconductor or metal into a sharp needle shape, and there is a problem that it becomes very expensive because a large-scale device is required.
[0005]
In view of the above, carbon nanotubes are recently attracting attention as emitters. Carbon nanotubes have a very small outer diameter of 1 to several tens of nanometers, and the shape tends to cause electric field concentration and has a sufficient structure to allow electron emission at a low voltage. It is an ideal material for the emitter because it is stable and mechanically strong.
[0006]
Accordingly, an electron emission source can be configured by forming a gate electrode after printing and baking a carbon material containing carbon nanotubes on a cathode electrode as an emitter. As the carbon material containing paste-like carbon nanotubes, a carbon material containing carbon nanotubes well dispersed by ultrasonic waves or the like in a solution obtained by dissolving an organic polymer material in an organic solvent can be used. In addition, an inorganic adhesive for fixing (for example, glass, metal alkoxide, etc.) is added as appropriate.
[0007]
In addition, if a fluorescent light-emitting display is formed by providing an anode electrode with a phosphor deposited opposite to the electron emission source and disposing them in a vacuum-tight container, the gate electrode and the anode electrode By driving to a positive potential, the phosphor can emit light by electron emission from the carbon nanotube.
[0008]
[Problems to be solved by the invention]
By the way, as the gate electrode, it is possible to use a mesh-like gate electrode disposed so as to face the emitter, but when driven by applying a voltage between the cathode electrode and the gate electrode, There is a problem that the gate electrode is likely to be short-circuited with the emitter due to thermal deformation or the like.
[0009]
As a method for solving this problem, as described in JP-A-10-31954, a cathode electrode is formed in a recess formed in the cathode substrate, and a carbon material paste containing carbon nanotubes is formed thereon. A method is conceivable in which an emitter is formed by firing after printing, and an electron emission source is formed by depositing a gate electrode on the convex portion of the cathode substrate. However, the method described in the above publication has a problem in that a complicated manufacturing process is required because a concave portion having a predetermined pattern is formed on the cathode substrate to form a cathode electrode, a gate electrode, an emitter, or the like. .
[0010]
As a method for solving this problem, a method is conceivable in which a paste of a carbon material containing carbon nanotubes is screen-printed on the cathode electrode as an emitter and then fired, and a rib-like gate electrode is formed between the emitters by screen printing.
However, even in this method, when the rib-shaped gate electrode is printed by screen printing, when the rib-shaped gate electrode is printed after the emitter is printed, the alignment treatment of carbon nanotubes contained in the emitter or carbon Even if the material is subjected to a sharpening process or the like for forming protrusions, the screen printing plate comes into contact with the emitter, and the orientation process or the sharpening process is wasted. In particular, when the emitter is formed in a dot shape and the rib-like gate electrode is formed in a lattice shape surrounding the emitter, such a problem becomes significant.
[0011]
In order to solve this problem, a method of forming the rib-like gate electrode before printing the carbon material can be considered, but it is difficult to print the carbon nanotube material between the rib-like gate electrodes. There was a problem.
In addition, since the distance between the gate electrode and the cathode conductor is short, there is a problem in that when the rib-shaped gate electrode is printed, the gate electrode and the cathode conductor are in contact with each other and insulation failure is likely to occur.
[0012]
The present invention has been made in view of the above problems, and it is an object of the present invention to suppress an insulation failure between a gate electrode and a cathode conductor and to enable easy manufacture.
[0013]
[Means for Solving the Problems]
According to the present invention, a first substrate having an insulating substrate, a cathode conductor formed on the insulating substrate, and a plurality of emitters electrically connected to the cathode conductor is separated from the plurality of emitters. Then, in the method of manufacturing an electron emission source by forming a gate electrode on the first substrate, a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules is used as the cathode for the cathode. Applying an adhesive between the plurality of emitters on the insulating rib or on the first substrate, the step of depositing the conductor, the step of laminating the gate electrode and the insulating rib on the second substrate And a plurality of emitters on the first substrate through the adhesive, the gate electrode and the insulating rib laminated on the second substrate. Transferring method of manufacturing an electron-emitting source, characterized by comprising a step of depositing is provided.
[0014]
An adhesive force between the insulating rib, the adhesive, and the first substrate is formed of a material that is larger than an adhesive force between the second substrate and the gate electrode.
Further, the first substrate is laminated and deposited with an insulating substrate, a cathode conductor, and an emitter formed of a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules. You may make it form.
[0015]
Furthermore, the first substrate is laminated and deposited with an insulating substrate, a cathode conductor, a resistance layer, and an emitter formed of a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules. It may be formed by doing so.
The method of manufacturing an electron emission source according to any one of claims 1 to 4, wherein the gate electrode is formed wider than the insulating rib.
[0016]
According to the present invention, an electron emission source manufactured by any of the methods described above is provided.
An electron emission source according to the present invention includes an insulating substrate, a cathode conductor formed on the insulating substrate, and a first substrate having a plurality of emitters electrically connected to the cathode conductor. In the electron emission source formed by forming a gate electrode on the first substrate apart from a plurality of emitters, the emitter is made of a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules. And an insulating rib formed on the first substrate between the emitters and the gate electrode formed on the insulating rib, wherein the gate electrode is formed from the insulating rib. Is also characterized by being formed wide.
Further, according to the present invention, the anode electrode on which the electron emission source and the phosphor are deposited is disposed in the vacuum hermetic container, and the electrons emitted from the electron emission source are projected onto the phosphor. In a fluorescent light emitting display that performs light emitting display, there is provided a fluorescent light emitting display characterized in that the electron emitting source manufactured as described above is used as each electron emitting source.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 10 illustrate a method of manufacturing an electron emission source according to a first embodiment of the present invention, an electron emission source manufactured by the method, and a fluorescent light emitting display using the electron emission source. FIG. The first embodiment will be described below with reference to FIGS. 1 to 10, the same reference numerals are given to the same parts.
[0018]
First, in FIG. 1, a silver wire is screen-printed and fired on an insulating substrate 101 such as borosilicate glass to form a cathode wiring 102 as a cathode conductor to a thickness of about 5 μm.
Next, as shown in FIG. 2, a graphite paste is screen-printed so as to be continuous with the cathode wiring 102, and a cathode electrode 103 as a cathode conductor is formed to a thickness of about 10 μm.
[0019]
Note that a resistor paste as a resistor layer may be laminated on the cathode electrode 103 in order to stabilize the electron emission characteristics and to prevent the cathode electrode from being destroyed due to excessive mission emission from the emitter. In this case, the cathode electrode 103 may be a thin film.
[0020]
On the other hand, a carbon material containing carbon nanotubes produced by an arc discharge method is dispersed in isopropanol (IPA), which is a dispersion medium, by ultrasonic waves, and a carbon material dispersion solution containing carbon nanotubes obtained as a result is obtained as shown in FIG. As shown in FIG. 4, the emitter 104 having a thickness of about 2 μm is formed by applying and depositing on the substrate 301 by spin coating and drying.
[0021]
In addition, when a dispersing agent is added at the time of dispersion | distribution of a carbon nanotube, in order to remove this, after apply | coating the dispersion solution of the carbon material containing a carbon nanotube to the board | substrate 301, it bakes. Also, as a coating method, various printing methods can be adopted depending on the state of the dispersion.
[0022]
Next, the substrate 301 in FIG. 3 is turned upside down, placed on the substrate obtained in FIG. 2 and brought into contact with the emitter 104 and the cathode electrode 103, and then the substrate 301 is removed. Thereby, as shown in FIG. 4, the plurality of emitters 104 are transferred onto the cathode electrode 103. A recess 401 is formed between the emitters 104. Here, the insulating substrate 101, the cathode wiring 102 as the cathode conductor, the cathode electrode 103 as the cathode conductor, and the emitter 104 that emits electrons constitute a first substrate.
As described above, when the resistor layer is laminated on the cathode electrode 103, the emitter 104 is formed on the resistor layer. In this case, the insulating substrate 101 and the cathode wiring as the cathode conductor are formed. 102, the cathode electrode 103 as a cathode conductor, the resistance layer and the emitter 104 constitute a first substrate.
[0023]
At this time, carbon nanotubes having a portion not wetted by the paste exist on the surface of the cathode electrode 103.
Therefore, as shown in FIG. 5, the insulating substrate 501 with the electric field applying electrode 502 formed in a solid shape made of aluminum attached to the lower portion is separated by a predetermined distance (for example, about 5 mm) substantially parallel to the insulating substrate 101. The electric field application electrode 502 is set to a positive potential with respect to the cathode electrode 103, and a predetermined strength (for example, about 1 kV / second) is provided in a direction substantially perpendicular to the insulating substrate 101 between the electric field application electrode 502 and the cathode electrode 103. mm) electric field is applied.
[0024]
As a result, the carbon nanotubes are polarized by electrostatic induction by the electric field, and the end portions of the carbon nanotubes exposed on the liquid surface of the paste-like cathode electrode 103 are oriented in a substantially vertical direction with respect to the insulating substrate 101. Give you the power.
As described above, a method of applying a magnetic field can be adopted as a method of applying a force that orients the carbon nanotubes in a substantially vertical direction with respect to the insulating substrate 101.
[0025]
At the same time, a drying process at a predetermined temperature, for example, a drying process is performed by applying an air flow of about 150 ° C. to fix the emitter 104 to the cathode electrode 103. At this time, depending on manufacturing conditions, it may be natural drying.
As a result, as shown in FIG. 6, a large number of carbon nanotubes existing on the surface of the emitter 104 are inclined with respect to the direction perpendicular to the insulating substrate 101 or in a direction close thereto.
[0026]
On the other hand, as shown in FIG. 7, a second substrate in which a polypropylene substrate 702 as a transfer substrate is integrally formed on a reinforcing metal plate 701 is prepared, and a conductive material, for example, silver paste is applied on the polypropylene substrate 702. A gate electrode 703 having a thickness of about 5 μm is formed by being deposited by screen printing and drying.
[0027]
Next, a paste of an insulating material such as glass is screen-printed on the gate electrode 703 to form an insulating rib 704 having a thickness of about 40 μm, and an adhesive 705 such as an acrylic resin is applied on the insulating rib 704. Let dry. At this time, the drying conditions can be appropriately selected depending on the paste material and the like. Further, the width of the insulating rib 704 can be narrower than the width of the gate electrode 703.
[0028]
Thereafter, the substrate obtained in FIG. 7 is turned upside down, and this is transferred by being brought into pressure contact with the first substrate as shown in FIG.
That is, first, alignment is performed so that each gate electrode 703 is positioned in the recess 401 between the emitters 104, and then the adhesive 705 is brought into pressure contact with the insulating substrate 101 by roll pressing by the roller 801. Thereafter, the second substrate for transfer composed of the metal plate 701 and the polypropylene substrate 702 is removed.
[0029]
At this time, each material is selected so that the adhesive force between the insulating substrate 101 and the adhesive 705 is larger than the adhesive force between the polypropylene substrate 702 and the gate electrode 703 of the second substrate. As shown in FIG. 3, the gate electrode 703 and the insulating rib 704 are transferred and adhered via the adhesive 705 between the plurality of emitters 104 on the first substrate. Thereby, a rib-like gate electrode constituted by the rib 704 and the gate electrode 703 is formed on the first substrate, and a field emission type electron emission source is completed.
[0030]
As described above, a rib-like gate electrode can be easily formed between a plurality of emitters 104, and the rib-like gate electrode and the cathode conductor can be accurately aligned. Therefore, the problem that the rib-like gate electrode and the cathode conductor cause an insulation failure can be suppressed.
[0031]
Further, in the electron emission source thus obtained, the carbon nanotubes included in the emitter 104 are oriented in a direction perpendicular to or in the direction close to the insulating substrate 101, so that the high voltage can be obtained at a low voltage. This enables efficient electron emission and suppresses variations in the amount of electron emission.
In FIG. 7, the adhesive 705 is deposited on the insulating rib 704, but it may be deposited between the emitters 104 on the insulating substrate 101.
[0032]
Moreover, although the example of the carbon material containing a carbon nanotube was given as a material of the emitter 104, the carbon material etc. which contain fullerene, a nanoparticle, or a nanocapsule can also be used. That is, as the material for the emitter 104, a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules can be used.
[0033]
Next, a fluorescent light emitting display as shown in FIG. 10 is formed using the electron emission source manufactured by the method described above.
That is, in FIG. 10, a fluorescent light emitting display includes an insulating substrate 101 as a rear substrate formed of borosilicate glass or the like, an insulating substrate 1001 as a translucent front substrate formed of borosilicate glass or the like, and an insulating substrate. A vacuum hermetic container having a sealing glass 1004 for sealing the periphery of the substrates 101 and 1001 is provided.
[0034]
Further, as described above, a plurality of carbon materials including the cathode wiring 102 as the cathode conductor, the cathode electrode 103 as the cathode conductor connected to the cathode wiring 102, and the carbon nanotube are formed on the inner surface of the insulating substrate 101. The emitters 104 are stacked. In the recesses between the emitters 104, an insulating rib 704 is deposited on the insulating substrate 101 constituting the first substrate by an adhesive 705, and a gate electrode 703 is stacked and deposited on the insulating rib 704. Is attached.
On the other hand, on the inner surface of the insulating substrate 1001, an anode electrode 1002 and a phosphor 1003 attached to the anode electrode 1002 are stacked.
[0035]
In the case of a fluorescent light-emitting display device that displays characters, graphics, etc., the cathode electrode 103, the gate electrode 703, and the anode electrode 1002 are each formed in a matrix or specific electrodes are solid. It is formed as appropriate by forming other electrodes in a matrix. Also, in the case of a fluorescent light emitting display used as a light emitting element for a large screen display device, the respective electrode patterns are appropriately formed.
[0036]
In the fluorescent light emitting display having the above-described configuration, the phosphor emits light by supplying drive signals to the cathode electrode 103, the gate electrode 703, and the anode electrode 1002, and characters and graphics are displayed according to the formation pattern of each electrode and the drive signal. The light emitting display or the light emitting display as a light emitting element can be performed.
[0037]
FIG. 11 is a partial cross-sectional view for explaining an electron emission source manufacturing method according to the second embodiment of the present invention and an electron emission source manufactured by the method, and is the same as FIG. 1 to FIG. Are given the same reference numerals.
The second embodiment is different from the first embodiment in that the gate electrode 703 protrudes more toward the emitter 104 than the insulating rib 704, that is, the width of the gate electrode 703 is the same as that of the insulating rib 704. It is the point formed wider than the width | variety, and another structure and manufacturing process are the same.
[0038]
Thus, the gate electrode 703 is formed closer to the emitter 104 by making the width of the gate electrode 703 wider than the width of the insulating rib 704 so that the gate electrode 703 protrudes toward the emitter 104 side. Therefore, the electron emission efficiency can be improved. In addition, the gate electrode 703 can be formed immediately above the cathode electrode 103, and this has an effect of reducing not only the electron emission effect at a low voltage but also the spread angle of the emitted electrons.
[0039]
As described above, the manufacturing method of the electron emission source according to the present embodiment is electrically connected to the insulating substrate 101, the cathode conductor (cathode wiring 102 or cathode electrode 103) formed on the insulating substrate 101, and the cathode conductor. In a method for manufacturing an electron emission source, in which a gate electrode 703 is formed on a first substrate having a plurality of connected emitters 104 and spaced apart from the plurality of emitters 104, the carbon nanotube, the fullerene Applying a carbon material having at least one of nanoparticles and nanocapsules to the cathode conductor as an emitter 104, and laminating a gate electrode 703 and insulating ribs 704 on a second substrate; Adhesive 705 is applied between the plurality of emitters 104 on the insulating ribs 704 or on the first substrate. Then, the gate electrode 703 and the insulating rib 704 stacked on the second substrate are transferred and adhered to the recesses 401 between the plurality of emitters 104 on the first substrate via the adhesive 705. And a process. At this time, a material such as a polypropylene substrate 702 is used so that the adhesive strength between the insulating rib 704, the adhesive 705, and the first substrate is larger than the adhesive strength between the second substrate and the gate electrode 703. select.
[0040]
Therefore, since the gate electrode 703 can be formed with high precision alignment with the cathode conductor or the emitter 104, it is possible to suppress insulation failure between the gate electrode 703 and the cathode conductor. Since the gate electrode 703 can be formed on the first substrate by a simple method of transfer, manufacturing is facilitated. In particular, even when the emitter 104 is formed in a dot shape and the rib 704 and the gate electrode 703 are formed in a lattice shape surrounding the emitter 104, the formation position can be maintained with high accuracy and can be easily formed. .
[0041]
Further, by making the width of the gate electrode 703 wider than the width of the insulating rib 704 so that the gate electrode 703 protrudes to the emitter 104 side than the insulating rib 704, low voltage driving is possible and electron emission is possible. The efficiency can be improved and the spread angle of the emitted electrons can be reduced.
[0042]
In addition, the above manufacturing method provides an electron emission source capable of suppressing the short circuit between the electrodes and stably emitting electrons.
Further, an anode electrode 1002 to which an electron emission source and a phosphor 1003 are attached is disposed in a vacuum hermetic container, and light emitted from the electron emission source is projected onto the phosphor 1003 for light emission display. By using the electron emission source manufactured as described above in the fluorescent light emitting display, it is possible to provide a fluorescent light emitting display capable of performing stable light emitting display.
[0043]
【The invention's effect】
According to the present invention, it is possible to easily manufacture without causing an insulation failure between the gate electrode and the cathode conductor.
This makes it possible to provide an electron emission source that can stably emit electrons.
Further, it is possible to provide a fluorescent light emitting display capable of performing stable light emission display.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view for explaining a method for manufacturing an electron emission source according to a first embodiment of the present invention.
FIG. 2 is a partial side cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 3 is a partial cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 4 is a partial side cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 5 is a partial cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 6 is a partial cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 7 is a partial cross-sectional view for explaining the manufacturing method of the electron emission source according to the first embodiment of the invention.
FIG. 8 is a partial side cross-sectional view for explaining the method for manufacturing the electron emission source according to the first embodiment of the invention.
FIG. 9 is a partial cross-sectional view for explaining the manufacturing method of the electron emission source according to the first embodiment of the invention.
FIG. 10 is a partially cutaway side view of the fluorescent light emitting display according to the first embodiment of the invention.
FIG. 11 is a partial cross-sectional view for explaining the method for manufacturing the electron emission source according to the second embodiment of the invention.
[Explanation of symbols]
101... A vacuum hermetic container and an insulating substrate 102 as a front substrate constituting the first substrate... Cathode wiring 103 as a cathode conductor constituting the first substrate... Cathode electrode 104 as a cathode conductor to constitute. Emitters 301, 501 ... substrate 502 ... electric field applying electrode 701 ... metal plate 702 constituting a second substrate ... -Polypropylene substrate 703 constituting the second substrate ... Gate electrode 704 ... Insulating rib 705 ... Adhesive 1001 ... Insulating substrate 1002 as the back substrate constituting the vacuum-tight container ... Anode Electrode 1003... Phosphor 805... Seal glass constituting vacuum hermetic container

Claims (6)

A first substrate having an insulating substrate, a cathode conductor formed on the insulating substrate and a plurality of emitters electrically connected to the cathode conductor, the first substrate being spaced apart from the plurality of emitters In a manufacturing method of an electron emission source formed by forming a gate electrode on a substrate,
Depositing a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles and nanocapsules on the cathode conductor as the emitter;
Laminating the gate electrode and the insulating rib on a second substrate;
Applying an adhesive between the plurality of emitters on the insulating rib or on the first substrate;
And transferring and depositing the gate electrode and the insulating rib laminated on the second substrate between the plurality of emitters on the first substrate via the adhesive. A method for manufacturing an electron emission source.   The adhesive rib, the adhesive, and the adhesive force between the first substrate are made of a material that is larger than the adhesive force between the second substrate and the gate electrode. 2. A method for producing an electron emission source according to 1.   The first substrate is formed by laminating and depositing an insulating substrate, a cathode conductor, and an emitter formed of a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules. 3. The method of manufacturing an electron emission source according to claim 1 or 2, wherein:   The first substrate is formed by laminating and depositing an insulating substrate, a cathode conductor, a resistance layer, and an emitter formed of a carbon material having at least one of carbon nanotubes, fullerenes, nanoparticles, and nanocapsules. The method of manufacturing an electron emission source according to claim 1, wherein the electron emission source is formed by:   The method of manufacturing an electron emission source according to claim 1, wherein the gate electrode is formed wider than the insulating rib.   An electron emission source manufactured by the method according to claim 1.

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