JP3478755B2 - Electron emitting element, electron source, and method of manufacturing image forming apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, an electron source, and a method for manufacturing an image forming apparatus. More specifically, a method of manufacturing an electron-emitting device in which a polyimide film having a small film thickness distribution is arranged by using an inkjet method on a conductive film electrically connected to a device electrode, an electron source using the same, and image formation The present invention relates to a method of manufacturing a device.

[0002]

2. Description of the Related Art Heretofore, two types of electron-emitting devices have been known, which are roughly classified into a thermoelectron-emitting device and a cold cathode electron-emitting device. The cold cathode electron-emitting device includes a field emission type, a metal / insulating layer / metal type, a surface conduction type electron-emitting device, and the like.

Regarding this surface conduction electron-emitting device,
For example, it is described in Japanese Patent Application Laid-Open No. 7-235255, and in Japanese Patent Application Laid-Open No. 9-237571, by repeatedly applying a pulse voltage between element currents in an atmosphere containing an organic substance, Of the organic substance, which does not require an activation step of depositing carbon and / or carbon compounds on the device, and a thermosetting resin, electron beam negative resist, polyacrylonitrile, etc. on the conductive film. Describes a method of manufacturing an electron-emitting device using an organic material previously applied, which comprises a step of applying the organic material and a step of carbonizing.

[0004]

An electron-emitting device including a coating step of coating a thermosetting resin, an electron beam negative resist, polyacrylonitrile, and other organic materials on a conductive film and a carbonization step of carbonizing them is used. In the manufacture of a flat image forming apparatus, if the organic material is applied uniformly in the step of applying the organic material, that is, if a certain amount of the organic material is applied with a certain film thickness, a uniform electron with no characteristic distribution is obtained. Emissive elements can be made.

As a method for applying the organic material, a spin coating method, that is, a method of dissolving the organic material in a solvent and spin-coating to secure a necessary film thickness of the organic material is disclosed in JP-A-9-237571. Have been described.

Further, Japanese Patent Application No. 9-174031 describes a method of applying a polyamic acid solution on a conductive film to form a polyimide film by an inkjet method. Since the solution prepared by only dissolving the polyamic acid in the organic solvent was applied, there was a tendency that the film thickness at the peripheral portion of the polyimide dot was thick and the film thickness at the central portion of the dot was smaller than that at the peripheral portion.

The device manufacturing method is to manufacture an electron-emitting device by coating a polyimide film on a conductive film electrically connected to a pair of device electrodes facing each other on a substrate to form an electron-emitting portion. Is. As a method of forming the electron emitting portion, a current is applied to the polyimide film to form a crack to form the electron emitting portion.

At this time, if a large film thickness distribution is generated in the polyimide dots, an electron emitting portion derived from the polyimide film is formed in the polyimide film on the conductive film, so that a portion having a large film thickness is subjected to the energization process. Of the polyimide film becomes conductive,
Not only the current related to the electron emission current, but also an ohmic current may flow, which reduces the electron emission efficiency and may not always be a good element.

[0009]

The present invention has been earnestly studied in order to solve the above-mentioned problems, and has the structure described below.

In an electron-emitting device having a conductive film electrically connected to a pair of opposing device electrodes on a substrate and having an electron-emitting portion in which an organic film is arranged on the conductive film, a polyimide film is used. When used, by forming a polyimide film having a small film thickness distribution on the conductive film, a part of the film becomes conductive when an electron-emitting portion derived from the polyimide film is formed in the polyimide film by conducting an electric current, and an electron is emitted. It has been found that not only the current related to the emission current but also an ohmic current flows and the electron emission efficiency does not decrease, and a good device can be obtained.

The organic film material applied on the conductive film preferably has high heat resistance because it undergoes a process of forming an electron emitting portion by energization and a baking process for cleaning. Polyether ether ketone, polyamide imide, polyimide, etc. are known as organic materials having heat resistance. From the viewpoint of high heat resistance and ease of film formation, polyimide is preferable because the precursor polyamic acid is solvent-soluble. Among the polyimides, wholly aromatic polyimides are particularly preferable in terms of heat resistance.

Polyamic acid which is a precursor of polyimide includes N-methylpyrrolidone (NMP), N, N-dimethylformamide (DMF) and dimethyl sulfoxide (D).
It dissolves well in organic solvents such as MSO. A polyimide film can be formed by applying this solution by an inkjet method, drying and baking.

The present inventor, when applying a solution of a polyamic acid, which is a precursor of polyimide, by an ink jet method and adding an organic amine to the polyamic acid solution, fires after the application to obtain a polyimide dot having a small film thickness distribution. I found that.

It is considered that this is because the polyamic acid and the organic amine react with each other to form an ammonium salt, which increases the viscosity, so that the ammonium salt of the polyamic acid in the central portion of the dot is difficult to move to the peripheral portion. As the organic amine used, alcohol amines such as diethanolamine, triethanolamine and trishydroxymethylaminomethane are preferable. When this solution of polyamic acid and organic amine is applied by an inkjet method and baked to form polyimide dots, the film thickness distribution of the polyimide dots increases the amine concentration when the organic amine concentration is in the range of 2% to 20%. As shown in the dot cross-sectional view (b) of the polyimide dot schematic diagram, the shape in which the film thickness in the peripheral portion is thick (FIG. 7B) is changed to the shape in which the film thickness is thick in the central portion (FIG.
The dot shape changes to (b ′)), and the ratio (FIG. 7, H1) of the film thickness in the dot peripheral portion (FIG. 7, H2) to the film thickness in the dot central portion (FIG. 7, H1) at that time. H2 / H1) is in the range of 2/1 to 1/2. Further, the concentration of the organic amine is preferable in view of the ejection property of the inkjet method and the viscosity of the solution.

Further, when the concentration of the polyamic acid is increased, the viscosity of the solution is increased, and the polyamic acid in the central portion of the dot tends to be difficult to move to the peripheral portion. Therefore, the concentration of polyamic acid is preferably 2% to 4%. This concentration is a concentration suitable for ejection because the ejection voltage is within the allowable range. A solution of polyamic acid to which an organic amine has been added as described above, that is, containing 2% to 20% of an organic amine, 2
% To 4% polyamic acid N-methylpyrrolidone (N
The thickness distribution of the polyimide dots by applying a solution dissolved in an organic solvent such as MP) by the inkjet method, the ratio of the film thickness of the dot peripheral part to the film thickness of the dot central part (film thickness of the dot peripheral part / Thickness at the center of the dot) 2/1
It was possible to obtain dots having a small film thickness distribution falling within the range of 1 to 1/2.

Thus, by applying the polyamic acid solution containing the organic amine by using the ink jet method in the applying step, it becomes possible to apply the polyimide organic film having a small film thickness distribution. For this reason, there is a possibility that a part of the polyimide film becomes conductive when the film is energized, and there is no possibility that an ohmic current will flow as well as the current involved in the electron emission current. It was

Further, according to the present invention, an electron emitting portion is obtained by arranging a polyamic acid containing an organic amine on a conductive film on a pair of electrodes provided on a substrate by an ink jet method and then firing the polyimide. A method of manufacturing an electron-emitting device having a method, in which a certain amount of polyimide can be formed on a conductive film by an inkjet method, so that an electron-emitting device can be easily manufactured, and a current-carrying treatment is performed to form a polyimide film having a small film thickness distribution. When this happens, part of the polyimide film becomes conductive, and not only the current involved in electron emission, but also ohmic current does not flow, resulting in a device with good electron emission efficiency and a long life, and a uniform image quality over a large area. The forming apparatus can be easily manufactured at low cost.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The basic structure of the surface conduction electron-emitting device of the present invention is shown in FIG. 3 (f), which is a plan view and a sectional view. An organic film is applied to explain the process of manufacturing the device. The process of applying the conductive film will be described.

FIG. 1 is a schematic view showing the structure of an element provided with a conductive film, wherein (a) is a plan view and (b) is a sectional view. Further, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, and 5 is an electron emitting portion.

As the substrate 1, quartz glass, glass having a reduced content of impurities such as Na, glass substrate laminated with SiO ₂ formed by sputtering or the like can be used.

The material of the opposing device electrodes 2 and 3 is as follows:
A general metal material can be used. In addition to the structure shown in FIG. 1, the conductive film 4 and the opposing device electrodes 2 and 3 may be stacked in this order on the substrate 1.

An example of a method of manufacturing the above surface conduction electron-emitting device will be described.

(1) The substrate 1 is thoroughly washed with a detergent, pure water, an organic solvent and the like, and after the element electrode material is deposited by a vacuum deposition method, a sputtering method or the like, the substrate 1 is deposited on the substrate 1 using, for example, a photolithography technique. Element electrodes 2 and 3 are formed on the substrate (FIG. 2A).

(2) On the substrate 1 provided with the device electrodes 2 and 3,
A metal compound solution is applied (droplet application) by an inkjet method (FIG. 2B), dried and baked to form a conductive film (FIG. 2C).

The metal compound film is dried and baked to form a conductive film, thereby forming a conductive film 4 for emitting electrons on the substrate. Drying process is usually used natural drying,
Blast drying, heat drying or the like may be used. For the firing step, a heating means that is usually used may be used. It is not always necessary to perform the drying step and the firing step as separate steps,
It does not matter if you go consecutively and simultaneously.

On the conductive film formed by the ink jet method, dissolved in an organic solvent such as NMP having a concentration of 2% to 4% of polyamic acid which is a precursor of polyimide containing 2% to 20% of alcohol amine by the ink jet method. The above solution is applied on a conductive film, dried and baked to form a polyimide film.

(3) Subsequently, a forming process is performed. As an example of the method of this forming step, a method by energization will be described. When power is applied between the device electrodes 2 and 3 by using a power source (not shown), the electron emitting portion 5 having a changed structure is formed at the site of the conductive film 4 (FIG. 2D). According to the energization forming, a site having a locally changed structure is formed in the conductive film 4. The portion constitutes the electron emitting portion 5. An example of the voltage waveform of energization forming is shown in FIG.

The voltage waveform is preferably a pulse waveform. For this, the method shown in FIG. 4 (a) in which a pulse having a constant pulse peak value is continuously applied, and the method shown in FIG. 4 (b) in which a voltage pulse is applied while increasing the pulse peak value. There is.

In FIG. 4A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. Normally T1 is 1 μsec
10 ms and T2 are set in the range of 10 μs to 100 ms. The peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens of minutes. The pulse waveform is not limited to the triangular wave, and a desired waveform such as a rectangular wave can be adopted.

T1 and T2 in FIG. 4 (b) are shown in FIG.
It can be similar to that shown in (a). The peak value of the triangular wave (peak voltage during energization forming) can be increased by, for example, about 0.1 V / step.

The end of the energization forming process can be detected by applying a voltage that does not locally break or deform the conductive film 4 during the pulse interval T2 and measure the current.

(4) Polyamine acid, which is a precursor of polyimide containing 2% to 20% of an organic amine, preferably an alcohol amine such as diethanolamine, triethanolamine, and trishydroxymethylaminomethane, is used for the element after the forming. 2% to 4% concentration of N
An organic solution such as MP is applied by an inkjet method. When applying, the polyamic acid solution is applied onto the conductive film by controlling the landing position so that the solution can be applied to the center of the conductive film. Since the diameter of the polyamic acid dot tends to widen as the number of times of repeated coating on the conductive film is increased, the number of times of application is preferably 5 times or less. The thickness of the polyimide film varies from 10 nm to 15 depending on the dot diameter, the density and the number of times of application.
It becomes 0 nm.

A polyimide film is formed by applying a polyamic acid solution on the conductive film, followed by drying and baking. (FIG.3 (e)). Then, an electric current is applied to form the polyimide film-derived electron emitting portion 7 (FIG. 3).
(F)).

The procedure shown in the above steps (3) and (4) may be reversed. That is, as (3 ′), on the conductive thin film 4 formed in the step (2),
A polyimide film is formed in the same manner as shown in (4) (FIG. 3 (g)).

After that, as (4 '), as in (3),
Conduct energization forming processing. As a result, the electron emitting portion 5 is formed and the electron emitting portion 7 derived from the polyimide film in the vicinity thereof is simultaneously generated.

In this surface conduction electron-emitting device, the electron emission characteristics can be easily controlled according to the input signal. By utilizing this property, it can be applied to various fields such as an electron source having a plurality of electron-emitting devices and an image forming apparatus.

As an application example of the above electron-emitting device, a plurality of surface-conduction electron-emitting devices can be arranged on a substrate to form, for example, an electron source or an image forming apparatus.

Further, the image forming apparatus of the present invention is used as an image forming apparatus as an optical printer constituted by using a photosensitive drum or the like, in addition to a display apparatus for television broadcasting, a display apparatus such as a video conference system or a computer. Can also be used.

[0039]

EXAMPLES Examples of the present invention will be described, but the present invention is not limited to the following examples.

[Embodiment 1] The electron-emitting device of this embodiment is
After manufacturing an element of the type shown in FIGS. 1 (a) and 1 (b),
A polyimide film was applied on the conductive film to prepare the film. Figure 1
FIG. 1A is a plan view of the element, and FIG. 1B is a sectional view. Further, 1 in FIGS. 1A and 1B is an insulating substrate,
2 and 3 are element electrodes for applying a voltage to the element, 4
Indicates a conductive thin film including an electron emitting portion, and 5 indicates an electron emitting portion. In the figure, L represents the element electrode distance between the element electrodes 2 and 3, and W represents the element electrode width.

A method of manufacturing the electron-emitting device of this embodiment will be described with reference to FIG.

As the insulating substrate 1, a substrate in which 0.5 μm of SiO _x was formed on the cleaned glass by the CVD method was used. After thoroughly washing it with an organic solvent, the surface of the substrate 1 was covered with platinum. Element electrodes 2 and 3 are formed (see FIG. 2).
(A)). At this time, the device electrode interval was 10 μm, the device electrode width W was 500 μm, and the thickness thereof was 100 μm.

Palladium acetate tetraethanolamine complex [Pd (H ₂ NC ₂ H ₄ OH) ₄ (CH ₃ COO) ₂ ]
0.6 g, 86% saponified polyvinyl alcohol (average degree of polymerization 500) 0.05 g, isopropyl alcohol 25
g and 1 g of ethylene glycol were added, and water was added to bring the total amount to 100 g to obtain a palladium compound solution.

This palladium compound solution was filtered through a membrane filter having a pore size of 0.25 μm and filled in a bubble jet head BC-01 manufactured by Canon Inc., and a DC voltage of 20 V was externally applied to a heater in a predetermined head for 7 μsec. By applying, a palladium compound solution was discharged to the gap portion between the device electrodes 2 and 3 on the quartz substrate. The ejection was repeated 5 more times while maintaining the positions of the head and the substrate. The droplets were almost circular and had a diameter of about 110 μm. This substrate is placed in an oven at 350 ° C in the atmosphere for 30
When the metal compound was decomposed and deposited on the substrate by heating for minutes, a palladium oxide film was formed.

Next, as shown in FIG. 2D, a voltage is applied to the electron-emitting portion 5 between the device electrodes 2 and 3, and the thin film 4 for forming the electron-emitting portion is energized (forming). It was produced by.

FIG. 4 shows the voltage waveform of the forming process.

In FIG. 4, T1 and T2 are the pulse width and the pulse interval of the voltage waveform. In this experimental example, T1 is 1 millisecond,
T2 is 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) is 5V, and the forming process is about 1
It was carried out for 60 seconds in a vacuum atmosphere of × 10 ^-6 Pa.

Then, using a piezo head, a solution of 2% polyamic acid and 2% triethanolamine in N-methylpyrrolidone (NMP) was aligned with the center of the circular palladium oxide film, and a 25 V triangular wave was applied. When ejected and baked at 350 ° C. for 30 minutes, the ratio of the peripheral film thickness / the central film thickness of the polyimide dot was 2.0.
The film thickness distribution is small.

Next, when a voltage having a bipolar pulse waveform was applied from 2.0 V between the device electrodes 2 and 3 to increase the voltage, a high resistance was exhibited at 14 to 18 V. According to scanning electron microscope (SEM) observation at this time, cracks were formed in the polyimide film along with the narrow cracks in the palladium oxide film caused by the forming treatment.

The electron emission characteristics of the device manufactured as described above were measured. FIG. 5 shows a schematic configuration diagram of the measurement / evaluation apparatus.

Also in FIG. 5, 1 is an insulating substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, 6 is a polyimide film, and 7 is a polyimide-derived electron emitting portion.
1 is a power supply for applying a voltage to the device, 50 is an ammeter for measuring the device current If, 54 is an anode electrode for measuring the emission current Ie generated from the device, 53 is a voltage for the anode electrode 54 High-voltage power supply for applying, 52
Is an ammeter for measuring the emission current. In measuring the device current If and the emission current Ie of the electron-emitting device, a power source 51 and an ammeter 50 are connected to the device electrodes 2 and 3, and a power source 53 and an ammeter 52 are connected above the electron-emitting device. The anode electrode 54 is disposed. The electron-emitting device and the anode electrode 54 are installed in a vacuum device, and the vacuum device is equipped with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), so that a desired vacuum can be obtained. The device can be measured and evaluated below. In this example, the distance between the anode electrode and the electron-emitting device was 4 mm, the potential of the anode electrode was 1 kV, and the pressure in the vacuum device at the time of measuring the electron emission characteristic was 1 × 10 ⁻⁶ Pa.

When a device voltage of 25 V was applied to the electrodes 2 and 3 of the present electron-emitting device by using the above-described measurement / evaluation device, the device current If was 0.5 mA and the emission current Ie was 3.
It became 7 μA. Since the thickness distribution of the polyimide film was made small, the device current If was small without flowing an ohmic current, and the ratio of emission current Ie / device current If was large.

Instead of the anode electrode 54, the face plate having the above-described fluorescent film and metal back was placed in a vacuum device. When an attempt was made to emit electrons from the electron source in this way, a part of the fluorescent film emitted light. Thus, it was found that this element functions as a light emitting display element.

[Example 2] An electron-emitting device was manufactured in the same manner as in Example 1.

As the insulating substrate 1, a substrate in which 0.5 μm of SiO _x was formed on the cleaned glass by the CVD method was used. After thoroughly washing it with an organic solvent, the surface of the substrate 1 was covered with platinum. Element electrodes 2 and 3 are formed (see FIG. 2).
(A)). At this time, the element electrode interval was 10 μm, the width W of the element electrode was 500 μm, and the thickness thereof was 100 μm.

Palladium acetate tetraethanolamine complex [Pd (H ₂ NC ₂ H ₄ OH) ₄ (CH ₃ COO) ₂ ]
0.6 g, 86% saponified polyvinyl alcohol (average degree of polymerization 500) 0.05 g, isopropyl alcohol 25
g and 1 g of ethylene glycol were added, and water was added to bring the total amount to 100 g to obtain a palladium compound solution.

This palladium compound solution was filtered through a membrane filter having a pore size of 0.25 μm and charged in a bubble jet head BC-01 manufactured by Canon Inc., and a DC voltage of 20 V was externally applied to a heater in a predetermined head for 7 μsec. By applying, a palladium compound solution was discharged to the gap portion between the device electrodes 2 and 3 on the quartz substrate. The ejection was repeated 5 more times while maintaining the positions of the head and the substrate. The droplets were almost circular and had a diameter of about 110 μm. This substrate is placed in an oven at 350 ° C in the atmosphere for 30
When the metal compound was decomposed and deposited on the substrate by heating for minutes, a palladium oxide film was formed.

Next, as shown in FIG. 2D, a voltage is applied to the electron emitting portion 5 between the device electrodes 2 and 3, and the electron emitting portion forming thin film 4 is energized (forming). It was produced by.

FIG. 4 shows the voltage waveform of the forming process.

In FIG. 4, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this experimental example, T1 is 1 ms,
T2 is 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) is 5V, and the forming process is about 1
It was carried out for 60 seconds in a vacuum atmosphere of × 10 ^-6 Pa.

Then, using a piezo head, a solution of 2% polyamic acid and 2% triethanolamine in N-methylpyrrolidone was aligned with the center position of the circular palladium oxide film, and a 25 V triangular wave was applied to the ejection. Let, 35
When baked at 0 ° C. for 30 minutes, the ratio of the thickness of the peripheral portion of the polyimide dot / the thickness of the central portion was 0.5. The film thickness distribution is small.

Next, when a voltage having a bipolar pulse waveform of 2.0 V was applied between the device electrodes 2 and 3 to increase the voltage, a high resistance was exhibited at 14 to 18 V. According to scanning electron microscope (SEM) observation at this time, cracks were formed in the polyimide film along with the narrow cracks in the palladium oxide film caused by the forming treatment.

The electron emission characteristics of the device manufactured as described above were measured. FIG. 5 shows a schematic configuration diagram of the measurement / evaluation apparatus.

Also in FIG. 5, 1 is an insulating substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, 6 is a polyimide film, and 7 is a polyimide-derived electron emitting portion.
1 is a power supply for applying a voltage to the device, 50 is an ammeter for measuring the device current If, 54 is an anode electrode for measuring the emission current Ie generated from the device, 53 is a voltage for the anode electrode 54 High-voltage power supply for applying, 52
Is an ammeter for measuring the emission current. In measuring the device current If and the emission current Ie of the electron-emitting device, a power source 51 and an ammeter 50 are connected to the device electrodes 2 and 3, and a power source 53 and an ammeter 52 are connected above the electron-emitting device. The anode electrode 54 is disposed. The electron-emitting device and the anode electrode 54 are installed in a vacuum device, and the vacuum device is equipped with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), so that a desired vacuum can be obtained. The device can be measured and evaluated below. In this example, the distance between the anode electrode and the electron-emitting device was 4 mm, the potential of the anode electrode was 1 kV, and the pressure in the vacuum device at the time of measuring the electron emission characteristic was 1 × 10 ⁻⁶ Pa.

When a device voltage of 25 V was applied to the electrodes 2 and 3 of the present electron-emitting device by using the above measuring and evaluating apparatus, the device current If was 0.5 mA and the emission current Ie was 3.
It became 8 μA. Since the thickness distribution of the polyimide film was made small, the device current If was small without flowing an ohmic current, and the ratio of emission current Ie / device current If was large.

Instead of the anode electrode 54, the face plate having the above-mentioned fluorescent film and metal back was placed in a vacuum device. When an attempt was made to emit electrons from the electron source in this way, a part of the fluorescent film emitted light. Thus, it was found that this element functions as a light emitting display element.

[Embodiment 3] The following embodiment is an example in which the energization forming treatment of the electron emitting portion is carried out after the polyimide film is coated on the conductive film.

As the insulating substrate 1, a substrate in which 0.5 μm SiO _x was formed on the cleaned glass by the CVD method was used. After thoroughly washing it with an organic solvent, the surface of the substrate 1 was covered with platinum. Element electrodes 2 and 3 are formed (see FIG. 2).
(A)). At this time, the element electrode interval was 10 μm, the width W of the element electrode was 500 μm, and the thickness thereof was 100 μm.

Palladium acetate tetraethanolamine complex [Pd (H ₂ NC ₂ H ₄ OH) ₄ (CH ₃ COO) ₂ ]
0.6 g, 86% saponified polyvinyl alcohol (average degree of polymerization 500) 0.05 g, isopropyl alcohol 25
g and 1 g of ethylene glycol were added, and water was added to bring the total amount to 100 g to obtain a palladium compound solution.

This palladium compound solution was filtered through a membrane filter having a pore size of 0.25 μm and filled in a bubble jet head BC-01 manufactured by Canon Inc., and a DC voltage of 20 V was externally applied to a heater in a predetermined head for 7 μsec. By applying, a palladium compound solution was discharged to the gap portion between the device electrodes 2 and 3 on the quartz substrate. The ejection was repeated 5 more times while maintaining the positions of the head and the substrate. The droplets were almost circular and had a diameter of about 110 μm. This substrate is placed in an oven at 350 ° C in the atmosphere for 30
When the metal compound was decomposed and deposited on the substrate by heating for minutes, a palladium oxide film was formed.

Using the piezo head, an N-methylpyrrolidone solution of 2% polyamic acid and 5% triethanolamine was aligned with the central position of the circular palladium oxide film on the element manufactured as described above. Then, a triangular wave of 25 V was applied and discharged, and the film was baked at 350 ° C. for 30 minutes, and the ratio of the peripheral film thickness of the polyimide dot / the central film thickness was 1.1. The film thickness distribution is small.

Next, a voltage was applied between the device electrodes 2 and 3, and the conductive film coated with the polyimide film was energized (forming process). FIG. 4 shows the voltage waveform of the forming process.

In FIG. 4, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this experimental example, T1 is 1 millisecond,
T2 was 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) was 8 V to 16 V, and the forming treatment was performed in a vacuum atmosphere of about 1 × 10 ⁻⁶ Pa. According to scanning electron microscope (SEM) observation at this time, cracks were formed in both the palladium oxide film and the polyimide film generated by the forming treatment.

The electron emission characteristics of the device manufactured as described above were measured. FIG. 5 shows a schematic configuration diagram of the measurement / evaluation apparatus.

Also in FIG. 5, 1 is an insulating substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, 6 is a polyimide film, and 7 is a polyimide-derived electron emitting portion.
1 is a power supply for applying a voltage to the device, 50 is an ammeter for measuring the device current If, 54 is an anode electrode for measuring the emission current Ie generated from the device, 53 is a voltage for the anode electrode 54 High-voltage power supply for applying, 52
Is an ammeter for measuring the emission current. In measuring the device current If and the emission current Ie of the electron-emitting device, a power source 51 and an ammeter 50 are connected to the device electrodes 2 and 3, and a power source 53 and an ammeter 52 are connected above the electron-emitting device. The anode electrode 54 is disposed. The electron-emitting device and the anode electrode 54 are installed in a vacuum device, and the vacuum device is equipped with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), so that a desired vacuum can be obtained. The device can be measured and evaluated below. In this example, the distance between the anode electrode and the electron-emitting device was 4 mm, the potential of the anode electrode was 1 kV, and the pressure in the vacuum device at the time of measuring the electron emission characteristic was 1 × 10 ⁻⁶ Pa.

When the device voltage Vf25V of the electrodes 2 and 3 of the present electron-emitting device was applied using the above measuring and evaluating apparatus, the device current If was 0.46 mA and the emission current Ie.
Was 3.8 μA. Since the thickness distribution of the polyimide film was made small, the device current If was small without flowing an ohmic current, and the ratio of emission current Ie / device current If was large.

Instead of the anode electrode 54, the face plate having the above-mentioned fluorescent film and metal back was placed in a vacuum device. When an attempt was made to emit electrons from the electron source in this way, a part of the fluorescent film emitted light. Thus, it was found that this element functions as a light emitting display element.

[Embodiment 4] A large-screen substrate (20 cm × 20 c) on which a large number of device electrodes and matrix wiring are formed.
m), the liquid droplets of the organometallic compound solution were applied to each of the counter electrodes in the same manner as in Example 1 using a bubble jet type ink jet device, and then fired (FIG. 2).
(C)), on the formed element (see FIG. 2).
(D)), using a piezo head, 2% polyamic acid,
A N-methylpyrrolidone solution of 5% triethanolamine was aligned with the center position of the circular palladium oxide film, a triangular wave of 25 V was applied and discharged, and baking was performed at 350 ° C. for 30 minutes. The ratio of the film thickness / the film thickness in the central portion was 1.1. The film thickness distribution is small.

Next, when a voltage was applied between the device electrodes 2 and 3, a high resistance was obtained at 14 to 18V.

A rear plate 81 and a support frame 82 face plate 96 were connected to this electron source substrate and vacuum-sealed to manufacture an image forming apparatus having a drive circuit according to the conceptual diagram of FIG. By applying a predetermined voltage in a time division manner to each element through the terminals Dox1 to Dox16 and the terminals Doy1 to Doy16 and applying a high voltage to the metal back through the terminal Hv, it is possible to display an arbitrary matrix image pattern and obtain a uniform image quality. Image forming apparatus.

[0081]

According to the present invention, 2% to 2% of an organic amine, which is a precursor of polyimide, is formed on a pair of electrodes provided on a substrate.
When a polyimide film having a small film thickness distribution is applied on the conductive film by applying a solution of polyamic acid containing 0% by an inkjet method, and an electron emitting portion is formed on the polyimide film by applying an electric current, The present invention is an efficient and uniform electron-emitting device in which an ohmic current does not flow other than a current which is partially conductive and contributes to an emission current, and a method for manufacturing an electron-emitting device.

Further, since a certain amount of polyimide having a small film thickness distribution can be applied onto the conductive film by the ink jet method, an electron-emitting device can be easily manufactured, and when the electron-emitting portion derived from the polyimide film is formed, the film thickness is reduced. An excessively thick portion does not become conductive, a device having a good electron emission efficiency and a long life can be formed, and an image forming apparatus having a uniform image quality over a large area can be easily manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a schematic plan view and a sectional view showing an element before forming an organic film of the present invention.

FIG. 2 is a schematic diagram showing the first half of an example of a method for manufacturing a surface conduction electron-emitting device of the present invention.

FIG. 3 is a schematic view showing the latter half of an example of a method for manufacturing a surface conduction electron-emitting device of the present invention.

FIG. 4 is a schematic view showing an example of a voltage waveform in an energization forming process which can be adopted in manufacturing the surface conduction electron-emitting device of the present invention.

FIG. 5 is a schematic diagram showing an example of a vacuum processing apparatus having a measurement / evaluation function.

FIG. 6 is a schematic diagram showing an example of a display panel of an image forming apparatus having a simple matrix arrangement according to the present invention.

FIG. 7 is a schematic plan view and a sectional view of a polyimide dot shape according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base | substrate 2,3 Element electrode 4 Conductive film 5 Electron emission part 6 Polyimide film 7 Polyimide film origin electron emission part 50 Ammeter 51 for measuring the element current If which flows through the electroconductive film 4 between element electrodes 2 and 3 Power supply 52 for applying the device voltage Vf to the electron emitting device 52 Ammeter 53 for measuring the emission current Ie flowing between the electron emitting portion 5 and the anode electrode 54 High voltage power supply 54 for applying the voltage to the anode electrode 54 Device Anode electrode 55 for capturing the emission current Ie emitted from the electron emission part of the device Evacuation device 56 Exhaust pump 71 Electron source base 72 X direction wiring 73 Y direction wiring 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support Frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 88 Envelope

Claims (4)

(57) [Claims] 1. A method of manufacturing an electron-emitting device having a conductive film electrically connected to a pair of device electrodes facing each other on a substrate, and having an electron-emitting portion in which an organic film is arranged on the conductive film. A step of applying a metal compound solution by an inkjet method , drying and firing to form the conductive film, applying a voltage between the pair of device electrodes, and cracking the conductive film. In order to express the film thickness distribution in the step of forming a film thickness (dot peripheral film thickness / dot central film thickness), a solution containing polyamic acid and amine is applied onto the conductive film by an inkjet method. And a step of forming an organic film having a film thickness distribution of 2/1 to 1/2, and a step of applying a voltage between the pair of device electrodes to form a crack in the organic film. Method of manufacturing electron-emitting device. 2. A method of manufacturing an electron-emitting device having a conductive film electrically connected to a pair of opposing device electrodes on a substrate, and having an electron-emitting portion in which an organic film is arranged on the conductive film. The step of applying the metal compound solution by an inkjet method , drying and baking the conductive film to form the conductive film, (the film thickness at the peripheral portion of the dot / the film thickness at the central portion of the dot) represents the film thickness distribution, On the conductive film , polyamic acid and amine
A step of applying a solution containing a film by an inkjet method to form an organic film having a film thickness distribution of 2/1 to 1/2, applying a voltage between the pair of device electrodes, and forming a film with the conductive film. A method of manufacturing an electron-emitting device, comprising a step of forming a crack in an organic film. 3. A method of manufacturing an electron source having a plurality of electron-emitting devices, said plurality of electron-emitting devices also claim 1
Is manufactured by the method described in 2 above. 4. An electron source having a plurality of electron-emitting devices,
In the manufacture of the image forming apparatus and an image forming member for forming an electron image by irradiation of emitted from the electron source, said plurality of electron-emitting devices are manufactured by a process according to claim 1 or 2 A method of manufacturing a characteristic image forming apparatus.