JP2002358874A - Method of manufacturing electron source and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an electron source which can form in a given thickness a conductive film of high resistance set for eliminating problems due to abnormal discharge phenomenon or the like, even in case there exists a porous member on a substance and, especially, can form a uniform conductive film by a spray coating method advantageous in cost. SOLUTION: In forming a conductive film 6 for an electron source provided with a plurality of electron emission elements, a plurality of wires for driving them, an insulating body 81 for insulating between the wires, and the conductive film 6 covering at least the insulating body 81, before a process of furnishing a composite including a conductor that is a component material for the conductive film and liquid medium at least on the surface of the insulating body 81, solution with all or part of the liquid medium as an ingredient is furnished at least on the surface of the insulating body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source having a plurality of electron-emitting devices and a method for manufacturing an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices using a thermionic electron-emitting device and a cold-cathode electron-emitting device are known. The cold cathode electron emission device includes a field emission type (hereinafter, referred to as “FE type”), a metal / insulating layer / metal type (hereinafter, referred to as “MIM type”), a surface conduction type electron emission device, and the like.

[0003] As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Fielddemissio
n ", Advance in Electron Ph
ysics, 8, 89 (1956), or C.I.
A. Spindt, “PHYSICAL Proper
ties of thin-film field e
mission cathodes with mol
ybdenum cones ", J. Appl. Phys.
s. , 47, 5248 (1976).

As an example of the MIM type, C.I. A. Mea
d, “Operation of Tunnel-Em
issue Devices ", J. Apply. P
hys. , 32, 646 (1961).

As an example of the surface conduction electron-emitting device,
M. I. Elinson, RadioEng. Elec
tron Pys. , 10, 1290, (1965) and the like. Surface conduction electron-emitting devices are
This utilizes a phenomenon in which electron emission occurs when a current flows through a small area thin film formed on a substrate in parallel with the film surface.

As the surface conduction type electron-emitting device, one using an SnO ₂ thin film by Elinson et al., Au
By a thin film [G. Dittmer: "Thin S
Solid Films ", 9, 317 (1972)],
In ₂ O ₃ / SnO ₂ by thin film [M. Hartwe
ll and C.I. G. FIG. Fonstad: “IEEEET
rans. ED Conf. 519 (197
5)], and those using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22, p. 22 (1983)] and the like have been reported.

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.P. Figure 13 shows the device configuration of Hartwell
Is shown schematically in FIG.

In FIG. 1, reference numeral 1 denotes a substrate, and 3 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern. An emission part 2 is formed.

The distance L between device electrodes in the figure is 0.5 to 1 m.
m and the width W ′ are set to 0.1 mm.

Conventionally, in these surface-conduction electron-emitting devices, the electron-emitting portion 2 is subjected to an energization process called energization forming in advance before the electron emission.
It was common to form

That is, the energization forming means applying a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 3 and energizing the conductive thin film 3 to locally destroy, deform or alter the conductive thin film. In other words, the purpose is to form the electron-emitting portion 2 in an electrically high-resistance state.

In the electron emitting portion 2, a crack is generated in a part of the conductive thin film 3, and electrons are emitted from the vicinity of the crack.

In the surface conduction type electron-emitting device subjected to the energization forming process as described above, a voltage is applied to the conductive thin film 3 and a current is caused to flow through the device to cause the electron-emitting portion 2 to emit electrons. .

FIG. 14 is a schematic diagram showing another configuration example of the surface conduction electron-emitting device, and FIG. 15 is a schematic diagram showing an example of a method of manufacturing the electron-emitting device of FIG.

In FIGS. 14 and 15, reference numeral 1 denotes a substrate;
Reference numeral 2 denotes an electron emitting portion, 3 denotes a conductive thin film, 4 and 5 denote device electrodes, 151 denotes a droplet applying device, and 152 denotes a droplet.

In manufacturing such a surface conduction electron-emitting device, first, device electrodes 4 and 5 are formed on a substrate 1 at a distance of L (FIG. 16A). Next, a droplet 152 made of a solution containing a metal element is ejected from a droplet applying device (inkjet recording device) 151 (FIG. 16).
(B)) The conductive thin film 3 is formed so as to be in contact with the device electrodes 4 and 5 (FIG. 16C). Next, a crack is generated in the conductive thin film by, for example, a forming process described later, and the electron-emitting portion 2 is formed (FIG. 16D).

By using such a droplet applying method, fine droplets of the contained solution can be selectively formed only at desired positions, so that the material constituting the conductive thin film is wasted. There is no. Further, a vacuum process that requires an expensive apparatus and patterning by photolithography including a number of steps are not required, so that the production cost can be significantly reduced.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arranged and formed over a large area because of its simple structure and easy manufacture.

Therefore, various applications that make use of this feature have been studied, for example, applications to a charged beam source, a display device, and the like.

As an example in which a large number of surface conduction electron-emitting devices are formed in an array, as will be described later, surface conduction electron-emitting devices are arranged in parallel, and both ends of each device are interconnected (also referred to as common interconnection). And an electron source in which a number of connected lines are arranged in a large number of rows (for example, Japanese Patent Application Laid-Open No. 64-031332).
JP-A-1-283737, JP-A-2-25755
No. 2).

In particular, in image forming apparatuses such as display apparatuses, flat panel display apparatuses using liquid crystal have been widely used in place of CRTs in recent years. However, they are not self-luminous and must have a backlight. There is a problem, and development of a self-luminous display device has been desired.

The self-luminous display device is an image forming device in which an electron source having a large number of surface conduction electron-emitting devices and a phosphor that emits visible light by electrons emitted from the electron source are combined. Devices (eg, US Pat. No. 5,066,883).

[0023]

However, in the case of the above-described prior art, the following problems have occurred.

For example, in an image forming apparatus, electrons emitted from the above-described electron-emitting device are accelerated and made incident on an image forming member made of a phosphor or the like to obtain luminance.

These electron-emitting devices are handled in a vacuum. One of the causes of the instability of the electron-emitting characteristics in a vacuum is that if the surface of the insulating substrate is exposed in the vicinity of the electron-emitting portion, the potential of the surface becomes high. The present applicant has confirmed that the electron emission becomes unstable and the electron emission becomes unstable (Japanese Unexamined Patent Publication No.
-072534).

That is, in an image forming apparatus which responds in response to an input signal, an insulating substrate is usually used because each electron-emitting device needs to be electrically separated.

However, when a high voltage is applied to the phosphor in the image display unit, an electric potential is generated on the insulating surface around the opposing electron-emitting device due to capacitance division determined by vacuum and the dielectric constant of the insulator. The better the insulation, the longer the time constant of this potential and the potential remains charged. Further, when electrons are emitted from the electron-emitting device in this state, the electrons also collide with the charged insulating surface. In this case, secondary electrons are generated when charged particles such as electrons and ions are injected into the surface of the insulating substrate due to acceleration of the electrons. Particularly under a high electric field, abnormal discharge is caused, and the electron emission characteristics of the device are significantly reduced.
In the worst case, it has been experimentally confirmed that the element is destroyed.

Although there is still no clear point about this abnormal discharge phenomenon, the surface is charged by the injection of electrons and ions emitted from the element, or the secondary electron emission on the charged insulating surface causes avalanche increase of electrons. It is conceivable to be doubled and discharged. In addition, when electrons emitted from the electron-emitting device collide with the anode on which the phosphor is formed, X-rays or ultraviolet rays may be emitted. It is also conceivable to charge the substrate surface.

For example, when the surface of the insulating substrate is irradiated with X-rays, photoelectrons are emitted as a result of the photoelectric effect, and the photoelectrons are attracted to the anode, so that the surface of the insulating substrate is charged to a positive potential. It is possible.

Since the influence of the charging of the insulating surface becomes more remarkable as the distance from the electron emission point becomes shorter, it is necessary to suppress the charging particularly in the vicinity of the electron emitting element.

For this reason, a high-resistance conductive film has been formed on an insulating surface by various methods.

For example, a method of forming a high-resistance conductive film by a vacuum evaporation method or a sputter evaporation method has good controllability of the film thickness, resistance value, etc., but requires a large-sized vacuum apparatus as the substrate size increases. This was disadvantageous in terms of cost because the time was long.

Recently, as a means for forming a high-resistance conductive film, a method of spray-coating a conductive material in a state of being dispersed in a solution has been developed. Since the film can be formed in a short time, it is extremely advantageous for cost reduction. Therefore, in addition to CRT,
Used in each field.

However, in the spray coating method, a liquid film is formed once on the substrate immediately after spraying, and the solvent evaporates to form a high-resistance conductive film. .

When a porous structure is present on the substrate, the liquid film formed on the substrate immediately after spraying is absorbed by the porous material, so that a high-resistance conductive film is formed with a predetermined thickness. There was a problem that was not done.

This phenomenon occurs when a large number of metal wirings and insulating layers formed by a screen printing method, a photo paste method, or the like are provided on a substrate, and a porous material is included in them. Had been a problem.

According to the present invention, in the manufacture of an electron source having a plurality of electron-emitting devices as described above and suitably applied as an electron beam source for an image forming apparatus or the like, in particular, a porous member is present on a substrate. Even in such a case, the main object is to be able to form a high-resistance conductive film having a predetermined thickness, which is provided to solve the above-described problem due to the abnormal discharge phenomenon or the like.

[0038]

The structure of the present invention to achieve the above object is as follows.

That is, according to the present invention, a plurality of electron-emitting devices, a plurality of wires for driving the electron-emitting devices, an insulator for insulating the wires, and a conductive material covering at least the insulator are provided on the substrate. In the method for manufacturing an electron source including a film, the step of forming the conductive film includes a step of applying a composition including a conductor as a constituent material of the conductive film and a liquid medium to at least a surface of the insulator. Prior to the step of applying the composition, a step of applying a solution containing all or only a part of the liquid medium components to at least the surface of the insulator, As a method of manufacturing an electron source.

The method for producing an electron source according to the present invention further includes, as further preferred features, that the conductor is a metal oxide and the liquid medium is an organic solvent, and that the solution is a dried residue. A solution having no composition "," the step of applying the composition and the step of applying the solution are performed by a spray coating method ", and" the sheet resistance of the conductive film is in the range of 10 ¹⁰ Ω to 10 ¹² Ω. The electron-emitting device has a pair of device electrodes arranged side by side at an interval, and a conductive thin film including an electron-emitting portion disposed between the pair of device electrodes. "The plurality of wirings include a plurality of X-direction wirings and a plurality of Y-direction wirings,
The plurality of electron-emitting devices are arranged near the intersection of the X-directional wiring and the Y-directional wiring. "

Further, according to a method of manufacturing an image forming apparatus of the present invention, there is provided a method of manufacturing an image forming apparatus having an electron source and an image forming member, wherein the electron source is manufactured by the above-described method of manufacturing an electron source of the present invention. It is characterized by doing.

According to the method of manufacturing an electron source of the present invention, especially when a large number of porous metal wirings or insulating layers formed by a screen printing method, a photo paste method or the like are provided on a substrate. In addition, a high-resistance conductive film provided to solve a problem due to an abnormal discharge phenomenon or the like can be formed with a predetermined thickness by a simple method.

That is, when a large number of porous materials are present on the substrate as described above, the two processes of evaporating and drying the liquid film formed by spray coating or the like and simultaneously absorbing the liquid film into the porous material are performed. Pass. At this time, if the rate of absorption into the porous material is higher than the rate of evaporation and drying, most of the thin liquid film is once absorbed into the porous material and then evaporated and dried. In this case, it is difficult to leave a conductive film having a required thickness on the substrate surface.

On the other hand, in the present invention, before applying the composition containing the conductor as the constituent material of the conductive film and the liquid medium, a solution containing all or only a part of the liquid medium components is applied in advance. By doing so, the liquid medium can be sufficiently impregnated in the porous material, and the composition can be applied in a state where the absorbing power into the porous material is weakened. It is possible to

[0045]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

Referring to FIGS. 1 to 12, a method of manufacturing an electron source and an image forming apparatus according to an embodiment of the present invention will be described.

First, the basic configuration of the electron source according to the embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a schematic configuration diagram showing a part of an electron source according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a substrate, and 4 and 5 denote element electrodes, which are connected to 72 X-directional wirings and 73 Y-directional wirings, respectively. Reference numeral 3 denotes a conductive thin film including an electron emitting portion, 2 denotes an electron emitting portion, and 6 denotes a conductive film (antistatic film).

Examples of the substrate 1 include quartz glass, glass having a reduced impurity content such as Na, blue plate glass, a glass substrate in which blue plate glass is laminated with SiO ₂ formed by a sputtering method or the like, ceramics such as alumina, and a Si substrate. Can be used.

Opposite device electrodes 4 and 5 and X-direction wiring 7
2. As the material of the Y-directional wiring 73, a general conductor material can be used. This is, for example, Ni, Cr, A
metals or alloys such as u, Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO ₂ , Pd
Metal or metal oxide and printed conductor composed of glass or the like, such as -ag, can be appropriately selected from In ₂ O ₃ -SnO ₂ or the like transparent conductor and semiconductor materials such as polysilicon of.

The gap interval between the device electrodes 4 and 5 and the length of the electron-emitting portion 2 are designed in consideration of the applied form and the like.

The gap interval between the device electrodes 4 and 5 can preferably be in the range of several hundred nm to several hundred μm.
More preferably, it can be in the range of several μm to several tens μm.

The length of the electron-emitting portion 2 can be in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics.

The film thickness d of the device electrodes 4 and 5 is several tens n.
m to several μm.

Here, the conductive thin film 3 including the electron emitting portion 2
Is preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is determined by the step coverage of the device electrodes 4 and 5 and the device electrodes 4 and 5.
The resistance is appropriately set in consideration of the resistance between them and the forming conditions to be described later, but is usually preferably in the range of several hundred pm to several hundred nm, more preferably 1 nm to 50 nm.
nm, and preferably a sheet resistance of 10 ⁷ Ω / □ or less.

The sheet resistance value of the conductive thin film 3 including the electron-emitting portion 2 is limited as a resistance value at which a good electron-emitting portion can be formed in a forming step of the electron-emitting portion 2 described later, that is, a forming step.

The sheet resistance is defined as R = Rs (l / w), where w is the width of the conductive thin film 3, l is the gap between the opposing electrodes 4 and 5, and R is the resistance of the thin film. Rs that satisfies

In order to form a good electron-emitting portion, the sheet resistance of the conductive thin film 3 is preferably in the range of 10 ³ Ω / □ to 10 ⁷ Ω / □.

However, after forming the electron-emitting portion 2, it is preferable that the voltage applied through the device electrodes 4 and 5 is sufficiently applied to the electron-emitting portion 2, and the conductive thin film 3 including the electron-emitting portion 2 is provided. Is preferably lower.
For this reason, as will be described in detail later, the conductive thin film 3 including the electron-emitting portion 2 is formed as a metal oxide semiconductor film having a sheet resistance of 10 ³ Ω / □ or more and 10 ⁷ Ω / □ and reduced after forming. Thus, it can be used as a metal thin film having lower resistance. Therefore, the lower limit of the resistance value of the conductive thin film 3 including the electron-emitting portion 2 in the final state is not particularly limited. Here, the resistance value of the conductive thin film 3 including the electron emission portions 2 means a resistance value measured in a region not including the electron emission portions 2.

The material constituting the conductive thin film 3 is Pd, P
t, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, metal such as Zn, Sn, Ta, W, Pb, PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , Hf
Borides such as B ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , GdB ₄ , TiC, ZrC, HfC, TaC, SiC, W
Carbides such as C, nitrides such as TiN, ZrN, HfN, S
It is appropriately selected from semiconductors such as i and Ge, carbon and the like.

The electron-emitting portion 2 is constituted by a high-resistance crack formed in a part of the conductive thin film 3 and depends on the thickness, film quality, and material of the conductive thin film 3 and a technique such as energization forming which will be described later. It will be.

In some cases, conductive fine particles having a particle size in the range of several hundred pm to several tens of nm exist inside the crack of the electron emitting portion 2. The conductive fine particles contain some or all of the elements of the material constituting the conductive thin film 3. In addition, the electron emitting portion 2 including the crack and the conductive thin film 3 in the vicinity thereof may contain carbon and a carbon compound.

The conductive film (antistatic film) 6 of this embodiment is formed on the entire substrate and covers all the insulating surfaces. The conductive film 6 may be formed so as to cover at least the insulator 81 that insulates between the wirings.

As described in the conventional example, the conductive film 6 is formed to have a resistance of 10 ¹⁰ Ω / □ in order to prevent discharge caused by charging.
It is preferable that the sheet resistance is about 10 ¹² Ω / □, and the sheet resistance is about 10 ⁸ Ω from the allowable value of the leakage current between the XY wirings.
/ □ is required to be a sheet resistance value or more.

Next, the manufacturing method of the present invention will be described with reference to FIGS. Note that FIG.
Also in FIG. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

5 (FIG. 3)
(A)).

2) On the substrate 1 provided with the device electrodes 4 and 5,
The Y-directional wiring 73 is formed of a conductive metal or the like formed by using a photosensitive paste printing method, a vacuum deposition method, a sputtering method, and a photolithographic method so as to be in contact with the device electrode 5 (FIG. 3B). .

3) An insulator (interlayer insulating layer) 81 is provided at least at the portion where the Y-direction wiring 73 and the X-direction wiring 72 intersect so that the two can be electrically separated from each other. The insulator 81 is made of SiO 2 formed by using a photosensitive paste printing method, a vacuum evaporation method, a sputtering method or the like and a photolithographic method.
_2. Formed in a desired shape with an insulator such as PbO, and in particular, the film thickness, material,
The manufacturing method is appropriately set (FIG. 3C).

4) The X-direction wiring 72 is
It is formed of a conductive metal or the like formed by using a photosensitive paste printing method, a vacuum deposition method, a sputtering method, or the like and a photolithographic method so as to cross the direction wiring 73 and to be in contact with the element electrode 4 (FIG. d)).

5) Next, droplets made of a solution containing a metal element are ejected from a droplet applying device (inkjet recording device), and the conductive thin film 3 is brought into contact with the element electrodes 4 and 5.
Is formed (FIG. 3E).

Here, a method of forming the conductive thin film 3 by a droplet applying device (inkjet recording device) will be further described.

A droplet made of a solution containing a metal element is discharged from a droplet applying device (inkjet recording device) with high precision and at high speed to an arbitrary position on a substrate. In this case, the conductive thin film 3 is formed at a position in contact with the device electrodes 4 and 5. After that, depending on the material used, heat treatment or the like is performed to stabilize the characteristics of the conductive thin film.

As a specific example of the droplet applying device, any device can be used as long as it can form an arbitrary droplet, and in particular, a range of about several tens to several tens ng is used. It is preferable to use an ink-jet type device which can be controlled by the above method and can easily form a small amount of droplets of about 10 ng to several tens ng. Examples of the ink jet type apparatus include an ink jet ejecting apparatus using a piezoelectric element or the like, a method in which bubbles are formed in a liquid by thermal energy, and the liquid is discharged as droplets (hereinafter, referred to as a bubble jet (registered trademark) method). And the like.

5) Next, prior to the formation of the conductive film 6, an appropriate amount of a liquid composed only of a solvent component is sprayed on the substrate 1 by a spray device, and the liquid film is infiltrated by the liquid film. The porous member is impregnated with the liquid from the liquid film to reduce its absorbing power.

6) Next, depending on the ambient temperature, vapor pressure, air flow, solvent type, structure of the porous material on the substrate, etc., the liquid film on the exposed surface is absorbed over a time interval of several seconds to several tens of seconds. After disappearing by evaporation, a solution containing a conductive film material is sprayed from a spray device different from the above to form a conductive film (antistatic film) 6 on all insulating surfaces on the substrate (FIG. 3).
(F)). Thereafter, depending on the material used, heat treatment or the like is performed to stabilize the characteristics of the conductive film 6.

Here, a method of forming the conductive film 6 by a spray device (liquid spray device) will be further described with reference to FIG.

First, the solution 10 is sprayed only from the solvent component from the spray device 9 to infiltrate the liquid film on the substrate, and the porous portion absorbs the solution sufficiently. Thereafter, a solution 8 containing a high-resistance conductive material as a main material is sprayed from a spray device 7 to form a conductive film 6 on the substrate.

The spray devices (liquid spray devices) 7 and 9
A general two-fluid nozzle of gas-liquid mixing or a one-fluid nozzle of a liquid pressurization type can be used.

The solution 8 for forming the conductive film 6 is preferably a solution capable of obtaining a uniform film. For example, conductive ultrafine particles mainly composed of a carbon material, tin oxide, chromium oxide, or the like may be used in an organic solvent. A dispersion or a solution in which a conductive material is dispersed in silicon oxide or the like can be preferably used.

7) Subsequently, a forming step is performed. As an example of a method of the forming step, a method by an energization process will be described.

When an electric current is applied between the device electrodes 4 and 5 using a power supply (not shown), an electron emitting portion 2 having a changed structure is formed at the portion of the conductive thin film 3 (FIG. 3 (g)). . That is, according to the energization forming, a portion of the conductive thin film 3 whose structure such as destruction, deformation or alteration is locally formed is formed, and this portion constitutes the electron emission portion 2.

FIG. 4 shows an example of the voltage waveform of the energization forming.

The voltage waveform is preferably a pulse waveform. For this purpose, a method shown in FIG. 4A for continuously applying pulses with a pulse peak value being a constant voltage, and a method of increasing the pulse peak value while increasing the pulse peak value are shown in FIG. There is a method shown in FIG. 4B for applying a pulse.

T ₁ and T ₂ in FIG. 4A are the pulse width and pulse interval of the voltage waveform, respectively. Usually T ₁
Is in the range of 1 μs to 10 ms, and T ₂ is in the range of 10 μs to
It is set in the range of 10 ms. The peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected according to the form of the electron-emitting device, and under such conditions, for example,
The voltage is applied for several seconds to several tens minutes.

The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted.

The values of T ₁ and T ₂ in FIG. 4B can be the same as those shown in FIG. The peak value of the triangular wave (peak voltage during energization forming) can be increased, for example, by about 0.1 V steps.

At the end of the energization forming process, a voltage that does not locally destroy or deform the conductive thin film 3 is applied during the pulse interval T ₂ , and the current is measured and detected. it can. For example, an element current flowing by applying a voltage of about 0.1 V is measured, and a resistance value is obtained. When the resistance shows 1 MΩ or more, the energization forming is terminated.

8) It is preferable to perform a process called an activation step on the element after the forming.

The activation step is, for example, 10 ⁻² to 10 ⁻³ P
A process of repeating application of a pulse with a pulse peak value of a constant voltage at a degree of vacuum of about a, and converts carbon and a carbon compound from an organic substance existing in a vacuum atmosphere into an electron emitting portion 2
This is a step in which the state of the device current and emission current can be significantly improved by depositing on the substrate. In introducing an organic substance, a gas of an appropriate organic substance may be introduced into a vacuum once sufficiently evacuated by a rotary pump or the like.
At this time, the preferable gas pressure of the organic substance varies depending on the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set depending on the case.

Suitable organic substances include organic acids such as aliphatic hydrocarbons of alkane, alkene and alkyne, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxylic acids, sulfonic acids and the like. Specific examples thereof include saturated hydrocarbons represented by C _n H _{2n + 2} such as methane, ethane, and propane, and unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as ethylene and propylene. Hydrocarbon, benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid, and the like, or a mixture thereof can be used.

This activation step is preferably performed while measuring, for example, the element current and the emission current, and, for example, is terminated when the emission current is saturated. The pulse peak value in the activation step is preferably the peak value of the drive voltage.

The above-mentioned carbon and carbon compound are graphite (indicating both single crystal and polycrystal) and amorphous carbon (indicating amorphous carbon and a mixture thereof with polycrystalline graphite). The deposited film thickness is preferably 50 nm or less, more preferably 30 nm or less.

9) The electron source obtained through such a step is preferably further subjected to a stabilization step.

This step is a step of exhausting the organic substance in the vacuum vessel. Here, it is preferable to use a vacuum evacuation device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a sorption pump,
A vacuum exhaust device such as an ion pump can be used.

In the activation step, when an oil diffusion pump or a rotary pump is used as an exhaust device and an organic gas derived from an oil component is used, the partial pressure of this component is kept as low as possible. There is a need.

The partial pressure of the organic component in the vacuum container is 1.3 at which the above-mentioned carbon and carbon compounds are not newly deposited.
× 10 ⁻⁶ Pa or less, more preferably 1.3 × 10 ⁻⁸ Pa
Pa or less is particularly preferred.

Further, when the inside of the vacuum vessel is evacuated,
It is preferable that the entire vacuum vessel is heated so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron source are easily exhausted.

The heating conditions at this time are desirably 80 to 250 ° C., preferably 150 ° C. or higher, and it is desirable to carry out the treatment for as long as possible. However, the present invention is not particularly limited to this condition. This is performed under conditions appropriately selected according to various conditions such as the structure of the above.

The pressure in the vacuum vessel must be as low as possible, preferably 1 × 10 ⁻⁵ Pa or less, and more preferably 1.3 × 10 ⁻⁵ Pa.
Particularly preferred is 10 ^-6 Pa or less.

The atmosphere at the time of driving after performing the stabilization step is preferably the same as the atmosphere at the end of the stabilization treatment, but is not limited to this. If the organic substance is sufficiently removed,

By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed.
Further, H ₂ O, O _2, etc. adsorbed on a vacuum vessel or a substrate can be removed, and as a result, the element current If and the emission current Ie are stabilized.

The basic characteristics of each electron-emitting device in the electron source obtained through the above steps will be described with reference to FIGS.

FIG. 5 is a schematic view showing an example of a vacuum processing apparatus. This vacuum processing apparatus also has a function as a measurement evaluation apparatus. In FIG. 5, only one electron-emitting device in the electron source shown in FIG. 1 is described, and the same parts as those shown in FIG. It is attached.

In FIG. 5, reference numeral 55 denotes a vacuum vessel;
Reference numeral 6 denotes an exhaust pump. An electron source is arranged in the vacuum vessel 55 (however, only a single electron-emitting device is shown in the drawing). Reference numeral 51 denotes a device voltage Vf applied to the electron-emitting device.
, A reference numeral 50 denotes an ammeter for measuring a device current If flowing through the conductive thin film 3 between the device electrodes 4 and 5, and a reference numeral 54 captures an emission current Ie emitted from the electron emission portion 2 of the device. An anode electrode for Also, 53
Is a high-voltage power supply for applying a voltage to the anode electrode 54,
Reference numeral 52 denotes an emission current Ie emitted from the electron emission portion 2 of the device.
Is an ammeter for measuring.

Here, as an example, the voltage of the anode electrode 54 is set in the range of 1 kV to 10 kV,
The measurement can be performed with the distance h between the device and the electron-emitting device in the range of 2 mm to 8 mm.

The vacuum vessel 55 is provided with equipment necessary for measurement in a vacuum atmosphere such as a vacuum gauge (not shown).
The measurement and evaluation can be performed in a desired vacuum atmosphere.

The exhaust pump 56 is composed of a normal high vacuum system including a turbo pump and a rotary pump, and an ultrahigh vacuum system including an ion pump and the like.

The entire vacuum processing apparatus provided with the electron source shown here can be heated by a heater (not shown).

Therefore, by using this vacuum processing apparatus, the steps subsequent to the energization forming described above can be performed.

FIG. 6 shows emission current Ie, device current If, and device voltage V measured using the vacuum processing apparatus shown in FIG.
It is the figure which showed the relationship of f typically.

In FIG. 6, since the emission current Ie is significantly smaller than the element current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is clear from FIG. 6, the electron-emitting device configured as described above has three characteristic properties with respect to the emission current Ie.

That is, (i) the present device has a certain voltage (referred to as a threshold voltage,
When an element voltage equal to or higher than Vth) is applied, the emission current Ie sharply increases. On the other hand, when the element voltage is equal to or lower than the threshold voltage Vth, the emission current Ie is hardly detected. That is, the emission current I
This is a non-linear element having a clear threshold voltage Vth for e. (Ii) Since the emission current Ie depends monotonically on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf. (Iii) The emission charge captured by the anode electrode 54 is:
It depends on the time for applying the element voltage Vf. That is, the amount of charge captured by the anode electrode 54 can be controlled by the time during which the device voltage Vf is applied.

On the other hand, the formation of the conductive film 6 does not affect the basic characteristics of the electron-emitting device. this is,
Since the resistance value of the conductive film 6 is sufficiently high (10 ⁸ Ω / □ or more), the leak current flowing through the conductive film 4 is sufficiently smaller than the device current observed during electron emission. That's why.

Further, since the sheet resistance of the conductive film 4 is sufficient to function as an antistatic film, charging of the substrate surface is also prevented. Therefore, the instability of the electron emission characteristics due to the potential instability of the substrate surface and the discharge between the vicinity of the element and the anode electrode are suppressed, so that stable electron emission characteristics for a long time can be obtained.

As can be understood from the above description, each electron-emitting device of the electron source configured as described above can easily control the electron-emitting characteristics in accordance with the input signal, and can maintain stable electron emission for a long time. Emission characteristic, that is, device current I
f, since it has a monotonically increasing characteristic of the emission current Ie with respect to the element applied voltage, it can be expected to be applied to various fields such as a large-screen image forming apparatus.

Next, the arrangement of the electron-emitting devices in the electron source to which the present invention can be applied will be described.

The arrangement of the electron-emitting devices in the electron source to which the present invention can be applied is such that a plurality of X-direction wirings 72 are provided on a plurality of Y-direction wirings 73 as shown in FIG. Insulating layer) 81, an X-directional wiring 72 and a Y-directional wiring 73 are connected to a pair of device electrodes 4 and 5 of the electron-emitting device, respectively. This is hereinafter referred to as a simple matrix arrangement. Hereinafter, this simple matrix arrangement will be described in detail.

According to the above-described basic characteristics of the electron-emitting device suitably used in the present invention, the emitted electrons in the above-described electron-emitting device arranged in a simple matrix are arranged such that, when the voltage exceeds the threshold voltage, the opposite device electrode is used. It can be controlled by the peak value and pulse width of the pulse voltage applied between them. On the other hand, below the threshold voltage, almost no electrons are emitted. Therefore, even when a large number of electron-emitting devices are arranged, if the pulse-like voltage is appropriately applied to each of the devices, the electron-emitting device can be selected according to the input signal, and the amount of electron emission can be controlled. Individual electron-emitting devices can be selected and driven independently only by the matrix wiring.

The simple matrix arrangement is based on such a principle and is an example of an electron source to which the present invention can be applied.
The configuration of the electron source having the simple matrix arrangement will be further described with reference to FIG.

In FIG. 7, 1 is a substrate, and 72 is X
Reference numeral 73 denotes a Y-direction wiring, 74 denotes an electron-emitting device, and 75 denotes a connection.

The m X-direction wirings 72 are Dx1, Dx
2,..., Dxm, and can be made of a conductive metal or the like formed by a printing method, a vacuum evaporation method, a sputtering method, or the like. The material, thickness, and width of the wiring are appropriately designed.

The Y-direction wiring 73 includes Dy1, Dy2,.
.., Dyn and are formed in the same manner as the X-directional wiring 72.

An insulator (interlayer insulating layer) (not shown) is provided between the m X-directional wirings 72 and the n Y-directional wirings 73.
Are provided, and both are electrically separated (m,
n is a positive integer).

An insulator (interlayer insulating layer), not shown, is formed of Si formed by a printing method, a vacuum evaporation method, a sputtering method, or the like.
The electron source substrate 1 is made of O ₂ , PbO, or the like, and is formed in a desired shape on the entire surface or a part of the electron source substrate 1 on which the X-directional wiring 72 is formed.
The film thickness, material, and manufacturing method are appropriately set so as to withstand the potential difference at the intersection of.

The X-direction wiring 72 and the Y-direction wiring 73 are respectively drawn out as external terminals.

Opposing device electrodes (not shown) constituting the electron-emitting device 74 are electrically connected to the m X-directional wires 72 and the n Y-directional wires 73 by a connection 75 made of a conductive metal or the like. ing.

The material forming the wiring 72 and the wiring 73, the material forming the connection 75, and the material forming the pair of element electrodes may be the same or different in some or all of the constituent elements. For example, the material is appropriately selected from, for example, the above-described materials of the element electrodes.

As will be described later in detail, a scanning signal applying means (not shown) for applying a scanning signal to scan the rows of the electron emitting elements 74 arranged in the X direction in accordance with an input signal is provided on the X-direction wiring 72. Is connected. On the other hand, the Y-direction wiring 73
Is connected to a modulation signal generating means (not shown) for applying a modulation signal in order to modulate each row of the electron-emitting devices 74 arranged in the Y direction according to an input signal.

The drive voltage applied to each electron-emitting device is:
It is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element.

Next, an example of an image forming apparatus using an electron source having a simple matrix arrangement as described above will be described with reference to FIGS.

FIG. 8 is a schematic diagram showing an example of the display panel of the image forming apparatus, which is partially cut away to show the inside. FIG. 9 is a schematic diagram of a fluorescent film used for the display panel of FIG.

In FIG. 8, reference numeral 1 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 101, a rear plate on which the electron source substrate 1 is fixed; 106, a fluorescent film 1 on the inner surface of a glass substrate 103;
This is a face plate on which a metal back 104 and a metal back 105 are formed. Reference numeral 102 denotes a support frame.
, A rear plate 101 and a face plate 106 are joined by using low melting point frit glass or the like to form an envelope 108.

Reference numerals 72 and 73 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the electron-emitting device 74, respectively.

As described above, the envelope 108 includes the face plate 106, the support frame 102, and the rear plate 101. The rear plate 101 is provided mainly for the purpose of reinforcing the strength of the substrate 1. If the substrate 1 itself has sufficient strength, the separate rear plate 101 can be dispensed with. That is, the support frame 10 is directly attached to the substrate 1.
2, the envelope 108 may be constituted by the face plate 106, the support frame 102, and the substrate 1.

Further, by providing a support (not shown) called a spacer between the face plate 106 and the rear plate 101, the envelope 108 having sufficient strength against the atmospheric pressure may be formed. it can.

In the case of monochrome, the fluorescent film 104 can be composed of only a phosphor.

In the case of a color fluorescent film, it is composed of a black conductive material 111 called a black stripe (FIG. 9A) or a black matrix (FIG. 9B) and a fluorescent material 112 depending on the arrangement of the fluorescent materials. be able to.

The purpose of providing a black stripe or a black matrix is to make the color separation between the phosphors 112 of the necessary three primary color phosphors black in color display to make color mixing and the like inconspicuous. The object is to suppress a decrease in contrast due to reflection of external light on the film 104.

As the material of the black conductive material 111, besides a commonly used material containing graphite as a main component, a material having conductivity and low light transmission and reflection can be used.

As a method of applying the phosphor on the glass substrate 103, a precipitation method, a printing method, or the like can be adopted regardless of monochrome or color.

A metal back 105 is usually provided on the inner side of the fluorescent film 104. The purpose of providing the metal back is to improve the brightness by mirror-reflecting the light toward the inner surface side of the emission of the phosphor toward the face plate 106 side, to act as an electrode for applying an electron beam acceleration voltage, The purpose is to protect the phosphor from damage caused by the collision of negative ions generated in the envelope 108.

The metal back is obtained by performing a smoothing treatment (usually called “filming”) on the inner surface of the fluorescent film after the fluorescent film is formed, and then depositing Al by vacuum evaporation or the like. Can be made.

In the face plate 106, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 104 in order to further increase the conductivity of the fluorescent film 104.

When performing the above-mentioned sealing, in the case of color, it is necessary to make each color phosphor correspond to the electron-emitting device.
Sufficient alignment is essential.

Image forming apparatus (display panel) shown in FIG.
An example of a method for manufacturing the above will be described below.

FIG. 10 is a schematic diagram showing an outline of an apparatus used in a manufacturing process of the image forming apparatus. Image forming apparatus 121
Is connected to a vacuum chamber 123 through an exhaust pipe 122, and is further connected to an exhaust device 12 through a gate valve 124.
5 is connected.

The vacuum chamber 123 has a pressure gauge 1 for measuring the internal pressure and the partial pressure of each component in the atmosphere.
26, a quadrupole mass analyzer 127 and the like are attached.

Since it is difficult to directly measure the pressure inside the envelope 108 of the image forming apparatus 121, the processing conditions are controlled by measuring the pressure of the vacuum chamber 123 and the like.

A gas introduction line 128 is connected to the vacuum chamber 123 to control the atmosphere by introducing a necessary gas into the vacuum chamber. An introduction substance source 130 is connected to the other end of the gas introduction line 128, and the introduction substance is stored in an ampoule or a cylinder.

In the middle of the gas introduction line 128, an introduction amount control means 1 for controlling the introduction rate of the introduced substance.
29 are provided. Specifically, as the introduction amount control means 129, a valve such as a slow leak valve which can control a flow rate, a mass flow controller, or the like is used.
Each can be used depending on the type of the substance to be introduced.

The inside of the envelope 108 is evacuated by the apparatus shown in FIG. 10 (note that the electron source at this point has not been subjected to the above-described forming process), and then forming is performed.
At this time, for example, as shown in FIG. 11, the Y-direction wiring 73 is connected to the common electrode 131, and a voltage pulse is simultaneously applied to the element connected to one of the X-direction wirings 72 by the power supply 132. Forming can be performed.

The conditions such as the pulse shape and the determination of the end of the processing may be selected in accordance with the above-described method for forming the individual elements.

Also, by sequentially applying (scrolling) a pulse with a phase shifted to a plurality of X-direction wirings, it is possible to form elements connected to the plurality of X-direction wirings collectively.

In FIG. 11, reference numeral 133 denotes a resistor for measuring current, and 134 denotes an oscilloscope for measuring current.

After the forming is completed, an activation step is performed.
After sufficiently exhausting the inside of the envelope 108, the organic substance is introduced from the gas introduction line 128. Alternatively, as described above, the individual elements may be activated by first evacuating with an oil diffusion pump or a rotary pump, and thereby using an organic substance remaining in a vacuum atmosphere. In addition, substances other than organic substances may be introduced as necessary.

By applying a voltage to each electron-emitting device in an atmosphere containing an organic substance formed as described above, carbon or a carbon compound, or a mixture of both, is deposited on the electron-emitting portion, and the amount of emitted electrons is increased. Rises drastically as in the case of the individual element.

At this time, a voltage can be applied by simultaneously applying a voltage pulse to the elements connected to one direction wiring by the same connection as in the above-described forming.

After the activation step is completed, it is preferable to perform a stabilization step as in the case of the individual element. In particular,
After the envelope 108 is heated and kept at 80 to 250 ° C., the exhaust is exhausted through the exhaust pipe 122 by an exhaust device 125 that does not use oil, such as an ion pump or a sorption pump, to obtain an atmosphere containing a sufficiently small amount of organic substances. Then, the exhaust pipe 122 is heated and melted by a burner and sealed.

In order to maintain the pressure after the envelope 108 is sealed, a getter process may be performed. This is, immediately before or after sealing the envelope 108,
This is a process of heating a getter disposed at a predetermined position (not shown) in the envelope 108 by heating using resistance heating, high-frequency heating, or the like to form a deposition film. The getter usually contains Ba or the like as a main component, and maintains the atmosphere in the envelope 108 by the adsorption action of the deposited film.

Next, an example of the configuration of a drive circuit for performing television display based on NTSC television signals on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG. .

In FIG. 12, 141 is an image display panel as shown in FIG. 8, 142 is a scanning circuit, 143 is a control circuit, 144 is a shift register, 145 is a line memory, 146 is a synchronization signal separation circuit, and 147 is modulation. The signal generators, Vx and Va, are DC voltage sources.

The display panel 141 has terminals Dox1 to Dox1
oxm, terminals Doy1 to Doyn, and high-voltage terminal H
It is connected to an external electric circuit via v.

Terminals Dox1 to Doxm are used to sequentially drive electron sources provided in the display panel, that is, electron emission element groups arranged in a matrix of m rows and n columns, one row (n elements) at a time. Are applied.

To the terminals Doy1 to Doyn, a modulation signal for controlling the output electron beam of each element of the one row of electron-emitting devices selected by the scanning signal is applied.

The high voltage terminal Hv is connected to a DC voltage source Va.
For example, a DC voltage of 10 kV is supplied, which is an accelerating voltage for applying sufficient energy to the electron beam emitted from the electron-emitting device to excite the phosphor.

The scanning circuit 142 has m switching elements therein (schematically indicated by S1 to Sm in the figure).
It is provided with. Each switching element selects either the output voltage of the DC voltage source Vx or 0 V (ground level), and the terminal Dox1 of the display panel 141.
To Doxm.

Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 143, and can be configured by combining switching elements such as FETs.

In the case of the present embodiment, the DC voltage source Vx uses a drive voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage Vth) of the electron emission element. It is set to output a constant voltage that is equal to or lower than Vth.

The control circuit 143 has a function of matching the operation of each section so that an appropriate display is performed based on an image signal input from the outside, and based on the synchronization signal Tsync sent from the synchronization signal separation circuit 146. , Tscan, Tsft, and Tmry for each unit.

The synchronizing signal separation circuit 146 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured.

The synchronization signal separated by the synchronization signal separation circuit 146 includes a vertical synchronization signal and a horizontal synchronization signal.
Here, it is illustrated as a Tsync signal for convenience of explanation.

The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. The DATA signal is input to the shift register 144.

The shift register 144 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 143. (Ie, the control signal Tsft can be said to be a shift clock of the shift register 144).

The data for one line of the image subjected to the serial / parallel conversion (corresponding to the drive data for n electron-emitting devices) is outputted from the shift register 144 as n parallel signals Id1 to Idn.

The line memory 145 is a storage device for storing data for one line of an image for a required time, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 143. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 147.

The modulation signal generator 147 outputs the image data I
The signal source is a signal source for appropriately driving and modulating each of the electron-emitting devices in accordance with each of d'1 to Id'n, and its output signal is supplied to the display panel 14 through terminals Doy1 to Doyn.
1 is applied to the electron-emitting devices.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie.

That is, a clear threshold voltage V is required for electron emission.
and electron emission occurs only when a voltage equal to or higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device.

Therefore, when a pulse-like voltage is applied to the device, for example, when a voltage lower than the electron emission threshold is applied, no electron emission occurs, but a voltage higher than the electron emission threshold is applied. In this case, an electron beam is output.

At this time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse.

Further, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.

Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device in accordance with an input signal.

When implementing the voltage modulation method, the modulation signal generator 147 generates a voltage pulse of a fixed length and modulates the peak value of the pulse appropriately according to input data. A circuit can be used.

When implementing the pulse width modulation method,
As the modulation signal generator 147, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 144 and the line memory 14
5 can be either a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 146 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 146. Just do it.

In connection with this, the circuit used for the modulation signal generator 147 differs slightly depending on whether the output signal of the line memory 145 is a digital signal or an analog signal.

That is, in the case of the voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 147, and an amplification circuit and the like are added as necessary.

In the case of the pulse width modulation system, the modulation signal generator 147 includes, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparison between the output value of the counter and the output value of the memory. A circuit in which a comparator (comparator) is combined is used.

If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier can be used as the modulation signal generator 147, and a level shift circuit and the like can be added as necessary.

In the case of the pulse width modulation system, for example, a voltage-controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the electron-emitting device can be added if necessary.

In the image display apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each of the electron-emitting devices via the external terminals Dox1 to Doxm and Doy1 to Doyn, the electron-emitting devices can emit electrons. Occurs.

The metal back 10 is connected via the high voltage terminal Hv.
5, or by applying a high voltage to a transparent electrode (not shown) to accelerate the electron beam. The accelerated electrons are transferred to the fluorescent film 104
And light is emitted to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention.

The input signal has been described using the NTSC system, but the input signal is not limited to this.
In addition to the SECAM method and the like, a TV signal (for example, a high-definition TV including the MUSE method) including a larger number of scanning lines can be adopted.

[0198]

The present invention will be described below with reference to more specific examples.

(Embodiment 1) The configuration of an electron source according to this embodiment is the same as the configuration shown in FIG. 1, and the manufacturing method thereof is basically the same as that of FIG. 2 and FIG. This is the same as described above. Hereinafter, a method for manufacturing an electron source in the present embodiment will be described.

[Step 1] A substrate 1 in which a silicon oxide film having a thickness of 1 μm is formed on a soda lime glass by a CVD method is washed with a detergent and pure water. Pattern the photoresist (RD-200
0N-41 manufactured by Hitachi Chemical Co., Ltd.), and a 5 nm-thick Ti and a 100 nm-thick Pt were sequentially deposited by a vacuum evaporation method.

Then, the photoresist pattern was dissolved with an organic solvent, the Pt / Ti deposited film was lifted off, and device electrodes 4 and 5 were formed so that the device electrode interval L was 20 μm and the device electrode width W was 200 μm ( FIG. 3 (a).

[Step 2] Next, using a photosensitive paste material mainly composed of Ag as a metal component, patterning was performed by photolithographic method after screen printing on the entire surface, and unnecessary portions were removed. Next, the patterned paste is fired by a heat treatment apparatus under the conditions of a peak temperature of 480 ° C. and a peak holding time of 10 minutes, and a thickness of about 10 μm.
(FIG. 3B). The wiring material formed by this method has porosity.

[Step 3] Next, using a photosensitive paste material containing PbO as a main component, the entire surface was screen-printed and then patterned by photolithography to remove unnecessary portions. Thereafter, firing was performed under the same conditions as in Step 2 to form an interlayer insulating layer 81 (FIG. 3C). In this embodiment, this process was repeated to ensure insulation stability, and the insulating layer was formed into a three-layer structure. As described above, this insulating layer also has porosity.

[Step 4] An X-directional wiring 72 was formed in the same manner as in step 2, using a photosensitive paste material containing Ag as a main component as a metal component (FIG. 3D). As described above, this wiring also has porosity.

[Step 5] Next, a conductive thin film 3 is formed. Specifically, the width W ′ of the conductive thin film 3 becomes 100 μm using an organic palladium-containing solution (ccp-4230, manufactured by Okuno Pharmaceutical Co., Ltd.) using a bubble jet (registered trademark) type inkjet ejecting apparatus. Element electrode 4,
5 was formed at the center of the gap. Then, at 350 ° C, 1
By performing heat treatment for 0 minutes, a fine particle film (conductive thin film 3) composed of fine palladium particles was obtained (FIG. 3E).

[Step 6] Subsequently, a conductive film 6 is formed.
Specifically, as shown in FIG. 2, a solution 10 made of isopropyl alcohol is preliminarily applied to the substrate while moving the spray nozzle 9 using a liquid pressurized one-fluid spray device, and the solution film is applied on the substrate for a short time. wet. 30 seconds later, a spray nozzle of a solution 8 in which ultrafine particles mainly composed of tin oxide are dispersed in an organic solvent (a mixed solution of isopropyl alcohol and ethyl alcohol) by a liquid pressurized one-fluid spray device of the same type as described above. 7 was moved and applied to the entire area to form a conductive film 6 (FIG. 3F).

In this embodiment, the average thickness of the conductive film 6 is 20 nm, the spray amount is 35 ml / min, the nozzle height is 150 mm, the nozzle moving speed is 50 cm / sec, and the sheet resistance is 10 ¹¹ Ω / □. Nozzle turn pitch amount 25
mm. Thereafter, heat treatment was performed at 380 ° C. for 10 minutes to stabilize the characteristics.

Next, a display panel as shown in FIG. 8 was manufactured by using the electron source substrate 1 in which a large number of unformed elements manufactured as described above were connected in a matrix in a wiring.

First, the electron source substrate 1 was placed on the rear plate 1
After fixing the substrate 1 with frit glass, the face plate 106 (glass substrate 1
03 is formed by forming a fluorescent film 104 and a metal back 105 on the inner surface of
Frit glass is applied to the joint between the face plate 106, the support frame 102, and the rear plate 101,
It sealed by baking at 00 degreeC for 10 minutes. The rear plate 101, the support frame 102, and the face plate 1
Reference numeral 06 is made of blue plate glass of the same material as the substrate 1.

The phosphor film 104 is made of only a phosphor in the case of monochrome, but in this embodiment, the phosphor is in a matrix shape, a black matrix is formed first, and each color phosphor is applied to the gap. Then, the fluorescent film 104 was manufactured. As a material of the black matrix, a material mainly containing graphite, which is generally used, was used. Note that a slurry method was used as a method of applying the phosphor on the glass substrate 103.

A metal back 105 was provided on the inner surface side of the fluorescent film 104. This metal back was produced by performing a smoothing treatment on the inner surface of the phosphor film after producing the phosphor film, and then performing vacuum deposition of Al.

In the face plate 106, a transparent electrode may be provided on the outer surface side of the fluorescent film 104 in order to further increase the conductivity of the fluorescent film 104. In this embodiment, however, only a metal back is sufficient for the conductive electrode. Was omitted because it was obtained.

When the above-mentioned sealing was performed, in the case of color, since the phosphors of each color had to correspond to the electron-emitting devices, sufficient alignment was performed.

The envelope 108 completed as described above
Is connected to the device shown in FIG. 10, and the atmosphere in the envelope 108 is exhausted by the exhaust device 125 through the exhaust pipe 122,
After reaching a sufficient pressure, as shown in FIG. 11, a voltage is applied between the electrodes 4 and 5 of the electron-emitting device 74 through the external terminals Dxo1 to Doxm and Doy1 to Doyn to form the conductive thin film 3. By processing
The electron emission part 2 was produced (see FIG. 3 (g)).

The voltage waveform of the forming process is shown in FIG.
Same as (b). The T ₁ in this embodiment is 1 ms, the T ₂ and 10 ms, it was carried out under a pressure of about 2 × 10 ^-3 Pa.

In the electron-emitting portion 2 thus prepared, fine particles mainly composed of palladium were dispersed and arranged, and the average particle size of the fine particles was 3 nm.

Next, acetone was introduced into the envelope 108 through the exhaust pipe 122 through the slow leak valve,
Pa was maintained.

Next, the triangular wave used in the forming process was changed to a rectangular wave, and the wave height was 14 V and the element current I was
f, the activation process was performed while measuring the emission current Ie.

By performing the forming and activating processes as described above, an electron source was obtained in which conductive thin films including a large number of electron-emitting portions 2 were connected by wiring in a matrix.

Next, the inside of the envelope was evacuated to a pressure of about 10 ⁻⁶ Pa, and the envelope was sealed by heating the exhaust pipe with a gas burner.

Finally, in order to maintain the degree of vacuum after sealing,
Getter treatment was performed by a high-frequency heating method.

In the display panel of this embodiment completed as described above (FIG. 8), each of the electron-emitting devices has a terminal D outside the container.
The scanning circuit and the modulation signal are applied from the driving circuit of FIG. 12 through ox1 to Doxm and Doy1 to Doyn, respectively, to emit electrons.
, An electron beam was accelerated by applying a high voltage of several kV or more through a high voltage terminal Hv to collide with the fluorescent film 104 to excite and emit light, thereby displaying an image.

Here, in this embodiment, all the insulating surfaces on the substrate are evenly covered with the conductive film 6 made of a high-resistance conductive material, so that the charge associated with electron emission is effectively prevented. As a result, the electron emission characteristics of each electron-emitting device were extremely stable, a stable image was displayed, no electron beam deflection occurred, and no destruction due to discharge was observed.

Example 2 In this example, the organic solvent (solution 10) used in [Step 6] of Example 1 was changed from isopropyl alcohol to n-butyl alcohol.
Accordingly, the time interval from the previous application of only the organic solvent to the application of the conductive film material solution (solution 8) is changed.

Steps before and after [Step 6] are the same as those in Embodiment 1, and therefore description thereof will be omitted. Hereinafter, [Step 6] of this example will be described.

[Step 6] Subsequently, a conductive film 6 is formed.
More specifically, as shown in FIG. 2, a solution 10 composed of n-butyl alcohol is preliminarily applied to the substrate while moving the spray nozzle 9 using a liquid pressurized one-fluid spray device, and the substrate is once coated with a solution film. Wait for the liquid film on the wetted exposed surface to evaporate and dry. After 60 seconds, a solution 8 in which ultrafine particles mainly composed of tin oxide are dispersed in an organic solvent (a mixed organic solvent of n-butyl alcohol and ethanol) is sprayed by a liquid pressurized one-fluid spray device of the same type as described above. The conductive film 6 is formed by coating the entire area while moving the nozzle 7.

In this embodiment, the spraying amount is 40 ml / min, the nozzle height is 150 mm, the nozzle moving speed is 40 cm / sec, and the average thickness of the conductive film 6 is 30 nm, and the sheet resistance is 10 ¹⁰ Ω / □. Nozzle turn pitch amount 25
mm. Thereafter, heat treatment was performed at 380 ° C. for 10 minutes to stabilize the characteristics.

Here, also in this embodiment, all the insulating surfaces on the substrate are evenly covered with the conductive film 6 made of a high-resistance conductive material, and the charge accompanying electron emission is effectively prevented. As a result, as in Example 1, the electron emission characteristics of each electron-emitting device were extremely stable, a stable image was displayed, no electron beam deflection occurred, and no destruction due to discharge was observed.

[0229]

As described above, according to the method of manufacturing an electron source of the present invention, even if a porous member is present on a substrate, it is possible to solve the problem due to the abnormal discharge phenomenon and the like. The high-resistance conductive film to be provided can be formed with a predetermined thickness. In particular, it has become possible to form the conductive film uniformly by a spray coating method which is extremely advantageous in cost.

Further, according to the method of manufacturing an image display device of the present invention, the process can be simplified, the reproducibility and uniformity of the entire display can be improved, and an image forming device capable of obtaining a higher quality image can be obtained. Further cost reduction is possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically showing a part of an electron source according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a manufacturing process of a conductive film in the electron source of FIG.

FIG. 3 is a view for explaining a manufacturing process of the electron source in FIG. 1;

FIG. 4 is a diagram showing a forming voltage waveform of the surface conduction electron-emitting device according to the embodiment of the present invention;

FIG. 5 is a basic measurement and evaluation device diagram of the surface conduction electron-emitting device according to the embodiment of the present invention.

FIG. 6 is a diagram showing the relationship between the emission current Ie, the device current If, and the device voltage Vf of the electron-emitting device according to the embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an electron source having a simple matrix arrangement according to an embodiment of the present invention.

FIG. 8 is a schematic configuration perspective view of an image forming apparatus according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a fluorescent film.

FIG. 10 is a schematic diagram of a vacuum exhaust device for performing a forming and activating process of the image display device according to the embodiment of the present invention.

FIG. 11 is a schematic diagram showing a connection method for performing a forming and activating process of the image forming apparatus according to the embodiment of the present invention.

FIG. 12 is a block diagram illustrating an example of a driving circuit for performing display in the image forming apparatus according to an NTSC television signal.

FIG. 13 is a plan view of an electron-emitting device according to the related art.

FIG. 14 is a plan view and a cross-sectional view of an electron-emitting device according to a conventional technique.

FIG. 15 is a drawing for explaining the method for manufacturing the electron-emitting device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part 3 Conductive thin film 4 Element electrode 5 Element electrode 6 Conductive film (antistatic film) 7 Nozzle 8 Solution containing conductive film material 9 Nozzle 10 Solution of organic solvent only 50 Ammeter 51 Power supply 52 Ammeter 53 High-voltage power supply 54 Anode electrode 55 Vacuum container 56 Exhaust pump 72 X-direction wiring 73 Y-direction wiring 74 Electron-emitting device 75 Connection 81 Interlayer insulating layer 101 Rear plate 102 Support frame 103 Glass substrate 104 Fluorescent film 105 Metal back 106 Face plate 108 Outer periphery Instrument 111 Black conductive material 112 Phosphor 121 Image display device 122 Exhaust pipe 123 Vacuum chamber 124 Gate valve 125 Exhaust device 126 Pressure gauge 127 Quadrupole mass spectrometer 128 Gas introduction line 129 Introduced amount control means 130 Introduced substance source 131 Common electrode 132 Power supply 133 Current measuring resistor 134 Oscilloscope 141 Display panel 142 Scanning circuit 143 Control circuit 144 Shift register 145 Line memory 146 Synchronous signal separation circuit 147 Modulation signal generator Vx and Va DC voltage source

Claims (8)

[Claims] 1. A substrate includes a plurality of electron-emitting devices, a plurality of wirings for driving the electron-emitting devices, an insulator for insulating the wires, and a conductive film covering at least the insulator on a substrate. In the method for manufacturing an electron source, the step of forming the conductive film includes the step of: applying a composition containing a conductor as a constituent material of the conductive film and a liquid medium to at least the surface of the insulator; Prior to the step of applying an object, a step of applying a solution containing all or only a part of the liquid medium components to at least the surface of the insulator. Production method. 2. The method according to claim 1, wherein the conductor is a metal oxide, and the liquid medium is an organic solvent. 3. The method according to claim 1, wherein the solution has no dry residue. 4. The method according to claim 1, wherein the step of applying the composition and the step of applying the solution are performed by a spray coating method. 5. A sheet resistance of said conductive film is 10 ¹⁰ Ω to 1
5. The method according to claim 1, wherein the value is within a range of 0 ¹² Ω.
The method for producing an electron source according to any one of the above. 6. The electron-emitting device according to claim 1, wherein the electron-emitting device includes a pair of device electrodes arranged side by side at intervals and a conductive thin film including an electron-emitting portion disposed between the pair of device electrodes. The method for manufacturing an electron source according to claim 1, wherein: 7. The method according to claim 7, wherein the plurality of wirings include a plurality of X-direction wirings and a plurality of Y-direction wirings.
7. The method according to claim 1, wherein the plurality of electron-emitting devices are arranged in the vicinity of the intersection of the X-direction wiring and the Y-direction wiring. . 8. A method for manufacturing an image forming apparatus having an electron source and an image forming member, wherein the electron source is manufactured by the manufacturing method according to claim 1. A method for manufacturing an image forming apparatus.