JPH07130280A - Manufacture of electron source material and electron source, and electron source and image forming device - Google Patents

Abstract

PURPOSE:To minimize the quantity of power required at forming so as to reduce the dispersion in formation of elements by interposing a bad heat conductor at the interface between an element electrode and the film consisting of an electron emitting material. CONSTITUTION:A film 2 for formation of an electron emitter is formed by forming an organic metallic film on an insulative substrate 1, and patterning it. A bad heat conductor 6 is made on the film 2 and it is patterned into a desired shape. Further, thereon metallic films or conductive films are laminated and patterned to form an element electrode 5. Subsequently, current application treatment is performed between the element electrodes 5 by pulse-shaped or high-speed boosted voltage, whereby an electron emitter 3, whose structure is changed, is formed at the section of the film 2. Hereby, it can be formed with low power consumption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source material for obtaining an electron source, a method for manufacturing the electron source, an electron source and an image forming apparatus such as a display device which is an application of the electron source.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitters, a thermoelectron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), a surface conduction electron emission element (hereinafter abbreviated as SCE), and the like. As an example of the FE type, W. P. Dyke & W.D. W. Dolan, "Fie
Idemission ”, Advance in El
electronic Electron Physic
s, 8, 89 (1956) or C.I. A. Spind
t, "PHYSICAL Properties of
thin-filmfield emission
cathodes with mollybdenium
cones ", J. Appl. phys., 47, 5
248 (1976) and the like are known. An example of the MIM type is C.I. A. Mead, "Thetunnel-em
"issue amplifier", J. Appl.
Phys. , 32,646 (1961) and the like are known. As an example of the SCE type, M. I. Elinson,
Radio Eng. Electron Phys. ，
10, (1965) and so on. The SCE type utilizes a phenomenon in which electron emission is caused by flowing a current in a thin film having a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using the SnO ₂ thin film by Erinson et al., One using the Au thin film [G. Dittmer: "Thin Solid Fi
lms ”, 9, 317 (1972)], In ₂ O ₃ / S.
nO ₂ thin film [M. Hartwell and
C. G. Fonstad: "IEEE Trans.
ED Conf. , 519 (1975)], by carbon thin film [Haraki Araki et al .: Vacuum, Vol. 26, No. 1
No., p. 22 (1983)] and the like.

FIG. 9 shows the above-mentioned Araki et al. As a typical element structure of these electron sources. 1 in the figure
Is an insulating substrate. 2 is a thin film for forming an electron emitting portion, which is H
The electron-emitting portion 3 is formed on the pattern of the mold shape by a metal oxide thin film or the like formed by sputtering or the like, and an energization process called forming, which will be described later. 4 will be referred to as a thin film including an electron emitting portion. Reference numeral 5 is an element electrode, which is used for forming or voltage application during driving.

Conventionally, in these electron sources, it is general that the electron emitting portion 3 is formed in advance by an energization process called forming before the electron emitting portion forming thin film 2 is emitted. That is, forming means that a voltage is applied to both ends of the electron-emitting-portion forming thin film 2 to locally destroy, deform or alter the electron-emitting-portion forming thin film so that the electron emitting portion has an electrically high resistance state. To form part 3. In the electron emitting portion 3, a crack is generated in a part of the electron emitting portion forming thin film 2, and electrons are emitted from the vicinity of the crack. Hereinafter, the electron emitting portion forming thin film 2 including the electron emitting portion formed by forming will be referred to as a thin film 4 including the electron emitting portion. The electron source that has undergone the forming process is a device that causes a voltage to be applied to the thin film 4 including the electron emitting portion 3 and causes a current to flow through the element so that the electron emitting portion 3 emits electrons.

The above-mentioned electron source has an advantage that a large number of elements can be arrayed over a large area because it has a simple structure and is easy to manufacture. Therefore, various applications that can make full use of this feature are being studied. Examples thereof include a charged beam source and a display device. As an example in which a large number of electron sources are arranged and formed, there is an electron source in which a large number of rows in which electron sources are arranged in parallel and both ends of each element are connected by wiring are arranged. (For example, Japanese Patent Laid-Open No. 1-0 of the present applicant
In addition, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystal have been used in CRTs.
However, since it is not a self-luminous type, there are problems such as having a backlight etc.
Development of a self-luminous display device has been desired. An image forming apparatus, which is a display device in which a large number of electron sources are arranged and a fluorescent substance that emits visible light is combined by electrons emitted from the electron sources, can be relatively easily manufactured even in a large screen device. In addition, the self-luminous display device is excellent in display quality. (For example, Applicant's USP 50666883)

[0006]

However, the above-mentioned conventional (surface conduction type) electron source material has the following problems. That is, in the forming step, electrons can be emitted by heating by energization, but the contact area between the device electrode and the electron emission portion forming thin film is inevitably large, so that the heat outflow increases and the power required for forming is increased. There was a problem that became large.

Furthermore, due to variations in the element shape in the manufacturing process, especially variations in the shapes of the end faces and the surface of the electrodes, the thermal resistances of the elements are greatly different, and even if forming is performed under a common voltage application condition, electron emission occurs. There is also a problem in that it is difficult to produce a good image forming apparatus whose characteristics differ from element to element.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and is an electron source material having a simple structure and capable of forming with low power consumption, a method of manufacturing the electron source, an electron source, and an image forming apparatus. In the electron source material having a device electrode and a thin film for forming an electron emission portion, at least a part of the interface between the device electrode and the thin film is provided via a poor heat conductor. In a vacuum atmosphere between the electron source material and the element electrode of the electron source material, characterized in that a power feeding portion is formed in a portion close to the center of the electron emission material forming thin film The present invention relates to a method of manufacturing an electron source, an electron source manufactured by the above manufacturing method, and an image forming apparatus incorporating the electron source, wherein energization processing is performed so as to apply a voltage.

The present invention will be described in more detail below.

FIG. 1 is a plan view and a sectional view showing an example of the electron source material of the present invention. Reference numeral 1 is an insulating substrate. Reference numeral 2 denotes a thin film for forming an electron emitting portion, which is composed of a metal oxide thin film or the like formed by sputtering or the like on an H-shaped pattern, and the electron emitting portion 3 is formed by forming described later. Also, 5
Is an element electrode used for forming or power supply during driving. Reference numeral 6 is a poor heat conductor such as an oxide.
Since the poor heat conductor 6 is provided between the electron emitting portion forming thin film 2 and the device electrode 5, the electron emitting portion forming thin film is thermally maintained while maintaining sufficient electrical contact. Since 2 is isolated from the outside world, the voltage required for forming can be smaller than that of the conventional element shown in FIG. It should be noted that the poor heat conductor 6 may be provided at least in a part of the interface between the device electrode 5 and the electron emission portion forming thin film 2.

FIG. 2 is a plan view and a sectional view showing another example of the electron source material of the present invention, in which a poor heat conductor 6 is provided between the electron emission portion forming thin film 2 and the device electrode 5. A power feeding point 7 is provided in a portion near the center of the electron emission portion forming thin film 2.
It is preferable to provide 7 because it is possible to suppress variations in the voltage distribution near the central portion of the electron emission portion forming thin film 2.

In the present invention, the parts before forming treatment shown in FIGS. 1 and 2 are referred to as electron source materials, and those obtained by subjecting the electron source material to forming treatment are referred to as electron sources.

Insulating group used in the electron source material of the present invention
The plate 1 has a reduced content of impurities such as quartz glass and Na.
A little glass, blue plate glass, blue plate glass spattering method, etc.
SiO formed by₂ Glass substrates, etc.
Examples include ceramics such as Lumina. Also of heat
As the defective conductor 6, SiO₂ , Alumina, beryllia, etc.
A thin film such as ceramics is used. Material of element electrode 5
As long as it has conductivity
Although it may exist, for example, Ni, Cr, Au, Mo,
Metals or alloys such as W, Pt, Ti, Al, Cu, Pd, etc.
And Pd, Ag, Au, RuO₂ , Metals such as Pd-Ag or
Is a printed conductor composed of metal oxide and glass, In
₂ O₃ -SnO₂ Such as transparent conductors and polysilicon, etc.
Examples include semiconductor conductor materials. The element electrode spacing L1 is
Hundreds of microns from hundreds of angstroms
Photolithography technology, which is the basis of the pole manufacturing method,
The performance of the exposure machine, the etching method, and the device electrode
Depending on the voltage applied between and the electric field strength that can emit electrons, etc.
However, preferably several to several tens of microns
Is. The element electrode length and the film thickness d of the element electrode 5 are
Resistance value, connection with the above-mentioned X and Y wirings, a large number are arranged
Designed appropriately according to the layout of the electron source
The electrode length is several hundreds of microns,
The film thickness d of the electrode 5 is preferably several hundred angstroms.
It is a few microns. In addition, the electron source material of FIG.
A thin film 2 for forming an electron emission portion, a poor heat conductor 6, on a substrate 1,
The element electrodes 5 are formed in this order, but on the insulating substrate 1.
Element electrode 5, defective heat conductor 6, electron emission portion forming thin film 2
You can create them in the order of. Also, the entire space between the device electrodes 5
However, depending on the manufacturing method, it may function as an electron emission unit.
is there. The film thickness of the electron emission portion forming thin film 2 is several angstroms.
Thousands of Angstroms, preferably tens of Angstroms
Hundreds of Angstroms more than Angstroms
Step coverage with the child electrode 5, electron emission unit 3 and device
Resistance value between electrodes 5 and particles of conductive fine particles in the electron emission portion 3
It is set appropriately according to the diameter, the energization processing conditions described later, etc.
It The resistance value is 10 7 to 10 7 ohm /
The sheet resistance value of □ is shown. The thin film 2 for forming the electron emission portion is constructed.
Specific examples of the material to be formed include Pd, Ru, and A.
g, Au, Ti, In, Cu, Cr, Fe, Zn, S
n, Ta, W, Pb, and other metals, PdO, SnO₂ , In
₂ O₃ , PbO, Sb₂ O₃ Oxides such as HfB₂ , Z
rB ₂ , LaB₆ , CeB₆ , YB_Four , GdB_Four Etc.
Compounds, TiC, ZrC, HfC, TaC, SiC, WC
Carbides such as TiN, ZrN, nitrides such as HfN, S
i, semiconductor such as Ge, carbon, AgMg, NiCu,
Pb, Sn and the like, which are composed of a fine particle film. Note that here
The sticky particle film is a film in which a plurality of particles are gathered,
As its fine structure, fine particles are individually dispersed and arranged.
Not only the particles are adjacent to each other or overlap each other
It refers to the film in the open state (including island shape). The number of electron emission parts 3 is
Thousands of Angstroms, preferably Angstroms
Is a particle size of 200 angstroms than angstroms
Thin film for forming electron emission part, consisting of many conductive fine particles
2 film thickness and forming energization processing conditions described later
It depends on the law etc. and is set appropriately. The electron emission part 3
The constituent material is the constituent material of the thin film 2 for forming the electron emission portion.
It is similar to some or all of the elements of the material.

Various methods are conceivable as a method of manufacturing the electron source having the electron emitting portion 3, one example of which is shown in FIG. Hereinafter, the manufacturing method will be described in order with reference to FIGS. 2 and 3. 1) The insulating substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, and then an organic metal solution is applied and left to stand to form an organic metal thin film. The organometallic solution means Pd, Ru, Ag, Au, Ti, In, Cu,
It is a solution of an organic compound containing a metal such as Cr, Fe, Zn, Sn, Ta, W, Pb as a main element. Then, the organic metal thin film is heated and baked, and is patterned by lift-off, etching or the like to form the electron emission portion forming thin film 2. (FIG. 3 (a)) Although the coating method of the organic metal solution has been described here, the present invention is not limited to this, and the vacuum vapor deposition method, the sputtering method, the chemical vapor deposition method, the dispersion coating method, the dipping method are not limited thereto. In some cases, it is formed by the spinner method or the like. 2) A poor thermal conductor film 6 is formed on the electron emission portion forming thin film 2 by a vacuum vapor deposition method, a sputtering method, spin coating of an organic complex solution of an oxide, or the like, and a photolithography technique is formed into a desired shape. Patterning by. (FIG. 3B) 3) Further, a metal film or a conductive film is laminated on the upper portion and patterned into a desired shape to form a device electrode 5. (FIG. 3 (c)) 4) Subsequently, when energization processing called forming is carried out by applying a voltage between the element electrodes 5 with a pulsed or high-speed rising voltage by a power source (not shown), an electron emitting portion is formed. An electron emitting portion 3 having a changed structure is formed at a portion of the thin film 2 for use. (FIG. 3D) The electron emission portion forming thin film 2 is locally destroyed, deformed or altered by this energization process, and a portion having a changed structure is called an electron emission portion 3. As described above, the present applicants have observed that the electron emitting portion 3 is composed of conductive fine particles.

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, where T1 is 1 microsecond to 10 milliseconds, and T2 is T2.
Was 10 microseconds to 100 milliseconds, the peak value of the triangular wave (peak voltage during forming) was about 4V to 10V, and the forming treatment was appropriately set in a vacuum atmosphere for about several tens of seconds. When forming the electron emission portion described above, the forming process is performed by applying a triangular wave pulse between the electrodes of the element, but the waveform applied between the electrodes of the element is not limited to the triangular wave, and the rectangular wave is not limited. A desired waveform may be used, and its crest value, pulse width, pulse interval, etc. are not limited to the above values, and a desired value can be selected as long as the electron emitting portion is formed well.

The basic characteristics of the electron source according to the present invention produced by the above element structure and manufacturing method will be described with reference to FIGS.

FIG. 5 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring the electron emission characteristics of the electron source having the configuration shown in FIG. In FIG. 5, 1 is an insulating substrate, 6 is a poor heat conductor, 5 is an element electrode, 4 is a thin film including an electron emitting portion,
Reference numeral 3 indicates an electron emitting portion. 31 is the element voltage V
A power supply for applying _f , 30 is an ammeter for measuring the device current I _f flowing through the thin film 4 including the electron emission part between the device electrodes 5, and 34 is an emission current emitted from the electron emission part of the electron source. An anode electrode for capturing I _e , 33 is a high-voltage power supply for applying a voltage to the anode electrode 34, and 32 is an emission current I emitted from the electron emission portion 3 of the electron source.
An ammeter for measuring _e . When measuring the device current _If and the emission current _Ie of the electron source, the device electrode 5 is used.
An anode electrode 34 in which a power source 31 and an ammeter 30 are connected in between, and a power source 33 and an ammeter 32 are connected above the electron source.
Are arranged. Further, the electron source and the anode electrode 34 are installed in a vacuum device, and the vacuum device is provided with equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown). The measurement and evaluation of can be performed. The voltage of the anode electrode is 1 kV to 1
0 kV, the distance H between the anode electrode and the electron source is 3 mm to 8
It was measured in the range of mm.

Further, as a result of earnestly examining the characteristics of the above-mentioned electron source according to the present invention, the present inventors found out the characteristic characteristic which is the principle of the present invention. FIG. 6 shows a typical example of the relationship between the emission current I _e and the device current _If and the device voltage V _f measured by the measurement / evaluation apparatus shown in FIG. In addition,
FIG. 6 is shown in arbitrary units because the magnitudes of I _f and I _e are significantly different. As is clear from FIG. 6, it has three characteristics with respect to the emission current I _e of the electron source.

First of all, when the electron source applies a device voltage higher than a certain voltage (called threshold voltage, V _{th in} FIG. 6), the emission current I _e rapidly increases, while the threshold voltage is increased. Voltage V
Below _th , almost no emission current I _e is detected. That is, it is a non-linear element having a clear threshold voltage V _th with respect to the emission current I _e .

Secondly, since the emission current I _e depends on the device voltage V _f , the emission current I _e can be controlled by the device voltage V _f .

Thirdly, the emitted charge trapped in the anode electrode 34 depends on the time for applying the device voltage V _f . That is, the amount of charges captured by the anode electrode 34 can be controlled by the time for which the device voltage V _f is applied. Since the electron source according to the present invention has the above characteristics, it can be expected to be applied to various fields.

Further, the element current I _f is (referred to as MI characteristic) monotonically increasing with respect to the device voltage V _f is an example of a characteristic shown in FIG. 6, the addition to the device current I _f of the element voltage V _In some cases, a voltage control type negative resistance (referred to as VCNR characteristic) characteristic is shown for _f . Also in this case, the electron source has the three characteristic features described above.

The basic manufacturing method is not limited to the above, and a part of the basic manufacturing method of the basic element structure of the present invention may be modified.

The electron source 74 of the present invention is arranged in a matrix on the substrate 1 as shown in FIG. 8, wirings 72 and 73 are formed in the vertical and horizontal directions of the substrate 1, and the surface facing the substrate is formed. Is provided with a face plate 86 via a support frame 82, and a face plate 86 including a fluorescent film 84 and a metal back 85 on the inner surface of the glass substrate 83, the support frame 8
2. Apply frit glass to the joint part of the rear plate 81, and 400 ° to 500 ° C. in air or nitrogen atmosphere.
It is sealed by baking for 10 minutes or more, and electrons are emitted by applying a scanning signal and a modulation signal to the respective electron sources through external terminals Dx1 to Dxm and Dy1 to Dyn from a signal generating means (not shown). High-quality image display can be performed by applying a high voltage of several kV or more to the metal back 85 through the high voltage terminal Hv.

[0025]

EXAMPLES The present invention will be described in more detail below with reference to examples. (Example 1) The electron source shown in FIG. 3 was produced by the following steps. Step-a Organic Pd (ccp4230, manufactured by Okuno Chemical Industries Co., Ltd.) was spin-coated on the cleaned blue plate glass, and the coating was performed at 300 ° C. for 10 hours.
It was heated and baked for 1 minute. In addition, the film thickness of the electron emission portion forming thin film 4 made of fine particles of Pd as the main element thus formed was 100 angstrom, and the sheet resistance value was 5 × 10 4 Ω / □. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above, and as a fine structure, not only the fine particles are individually dispersed and arranged, but also the fine particles are adjacent to each other or overlap each other. A film in a state (including an island shape) is referred to, and the particle diameter thereof means a diameter of fine particles whose particle shape can be recognized in the above state. Subsequently, a photoresist was spin-coated and patterned into an H shape by photolithography, and the electron emission portion forming thin film 4 was etched with an acid etchant to form a desired pattern. Where H
The size of the narrowed portion of the character is 10 microns wide and 300 microns long. Step-b Next, a photoresist is spin-coated, patterned by photolithography, and a heat-defective conductor 6 made of a silicon oxide film having a thickness of 0.5 μm is deposited thereon by RF sputtering. Subsequently, the resist pattern was dissolved in an organic solvent to lift off the heat-defective conductor layer 6. Step-c Next, a photoresist is spin-coated, patterned by photolithography, an Au / Cr film is deposited thereon to a thickness of 1000 Å, the resist pattern is dissolved in an organic solvent, and the Au / Cr film is lifted off. Then, the device electrode 5 was formed. Step-d Subsequently, after soldering the lead wire to the element electrode 5,
The electron emitting portion 3 was created by subjecting the electron emitting portion forming thin film 2 to an energization process (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 embodiment, T1 is 1 ms, T2 is 10 ms, and the peak value of the triangular wave (peak voltage during forming) is 3 V. ,
The forming treatment was performed for 60 seconds in a vacuum atmosphere of about 1 × 10 -6 torr.

In the electron-emitting portion 3 thus formed, fine particles containing palladium as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 Å.

The electron source produced through the above-mentioned steps exhibits electric characteristics (arbitrary unit) as shown in FIG. 6, and excellent electron emission in a vacuum atmosphere of about 1 × 10 −6 torr. Characterized. For comparison, when the step-b was omitted and a peak voltage during forming was set to 5 V or more to produce an electron source, it was confirmed that the electron source had substantially the same current-voltage characteristics. That is, according to the present invention, the electric power required for forming could be suppressed to 60% or less. (Embodiment 2) FIG. 7 shows a plan view and a sectional view of an electron source of this embodiment. In this embodiment, the device electrode 5, the poor heat conductor 6 and the electron emission portion forming thin film 2 are formed in this order on the insulating substrate 1. The production process is as follows. Step-a A photoresist is spin-coated on the cleaned soda lime glass, patterned by photolithography, an Au / Cr film is deposited thereon to a thickness of 1000 Å, the resist pattern is dissolved in an organic solvent, and Au is deposited.
The / Cr film was lifted off and the device electrode 5 was formed. Here, burrs remained on the end faces of the device electrodes 5, and the heights thereof varied among the devices. Step-b Next, silicon oxide alkoxide was spin-coated and baked by heating. Then, a photoresist was spin-coated, patterned by photolithography, and etched by an acid etchant to form a poor heat conductive layer 6. Step-c Next, a photoresist is spin-coated, patterned into an H shape by photolithography, and an organic P layer is formed thereon.
d (ccp4230 Okuno Seiyaku Co., Ltd.) was spin-coated and heated and baked at 300 ° C. for 10 minutes. In addition, the film thickness of the electron emission portion forming thin film 4 made of fine particles of Pd as the main element thus formed was 100 angstrom, and the sheet resistance value was 5 × 10 4 Ω / □. Here, the size of the H-shaped constricted portion is 10 microns in width and 300 microns in length. Step-d Subsequently, after soldering the lead wire to the element electrode 5,
The electron emitting portion 3 was created by subjecting the electron emitting portion forming thin film 2 to an energization process (forming process). The forming conditions are the same as in Example 1.

In the electron-emitting portion 3 thus produced, fine particles containing palladium as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 Å.

The electron source produced through the above steps shows the electrical characteristics (arbitrary unit) as shown in FIG. 6, and has a good electron emission in a vacuum atmosphere of about 1 × 10 −6 torr. Characterized. Further, not only a plurality of devices produced at the same time but also the devices produced in the same process had extremely good reproducibility.

For comparison, the step-b is omitted, and
Created multiple electron sources. If there is no heat-defective conductor layer 6,
Due to the effect of burrs on the device electrode 5, the forming method varies, and an electron source with good reproducibility cannot be produced. In other words, by forming the poorly heat-conductive layer by the method of spin coating of alkoxide, it becomes thicker according to the height of the burr of the element electrode, and it has the effect of self-correcting the variation of the burr. Conceivable. (Embodiment 3) Next, an example in which a display device is configured by using the electron source created by the method of Embodiment 2 will be described with reference to FIG.

First, a surface conduction electron-emitting device was produced on the substrate 1. Here, in order to arrange the electron sources in a matrix, in addition to the steps of Example 2, an insulating layer, a contact hole and the like for intersecting the device electrodes were formed by a normal semiconductor process. In FIG. 8, after the substrate 1 is fixed on the rear plate 81, the face plate 86 (the fluorescent film 84 on the inner surface of the glass substrate 83 is provided 5 mm above the substrate 1.
And a metal back 85 are formed through the support frame 82, and the face plate 86 and the support frame 8 are disposed.
2. Frit glass is applied to the joint portion of the rear plate 81, and the temperature is 400 ° C to 50 ° C in the air or nitrogen atmosphere.
It was sealed by baking at 0 ° C. for 10 minutes or more. The frit glass was also used to fix the substrate 1 to the rear plate 81. 74 is an electron-emitting device, and 72 and 73 are wirings in the X and Y directions, respectively. In the case of monochrome, the fluorescent film 84 is composed of only the fluorescent substance, but in the present embodiment, the fluorescent substance adopts a stripe shape, and a black stripe is first formed, and the fluorescent substance of each color is applied to the gap, and the fluorescent film is formed. 84 was produced. A material having graphite as a main component, which is commonly used as a material for the black stripe, is used, and a slurry method is used as a method for applying the phosphor to the glass substrate 83.
A metal back 85 is usually provided on the inner surface side of the fluorescent film 84. The metal back was manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then vacuum-depositing Al. The face plate 86 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 84 in order to further enhance the conductivity of the fluorescent film 84, but in the present embodiment, only a metal back is sufficient. The conductivity was obtained, so it was omitted. When performing the above-mentioned sealing, in the case of a color, the phosphors of the respective colors and the electron-emitting devices have to correspond to each other, so that sufficient alignment is performed.

The atmosphere inside the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the external terminals Dxo1 to Doxm and Doy1 to Doyn. A voltage is applied between the electrodes 5 of the electron-emitting device 74 through, and the electron-emitting portion 3 is formed by energizing (forming) the electron-emitting portion forming thin film 2. The forming conditions are the same as in the second embodiment. In the electron emitting portion 3 thus produced, fine particles containing palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 angstrom.

Next, an exhaust pipe (not shown) was heated by a gas burner to be welded at a vacuum degree of about 10 −6 torr to seal the envelope.

Finally, in order to maintain the degree of vacuum after sealing,
Getter processing was performed. Immediately before sealing, a getter placed at a predetermined position (not shown) in the image forming apparatus was heated by a heating method such as high-frequency heating to form a vapor deposition film. The getter was mainly composed of Ba or the like.

In the image display device of the present invention completed as described above, the scanning signal and the modulation signal are respectively supplied to the electron-emitting devices from the signal generating means (not shown) through the terminals Dx1 to Dxm and Dy1 to Dyn outside the container. , Is applied to cause electrons to be emitted, and a high voltage of several kV or more is applied to the metal back 85 through the high-voltage terminal Hv to accelerate the electron beam, collide with the fluorescent film 84, and cause excitation / light emission to display an image. did.

[0036]

As described above, according to the present invention, the amount of electric power required at the time of forming can be suppressed to a low level. Therefore, when considering heat radiation or the like when configuring the entire display device,
Afford. Furthermore, by providing a power supply location near the center of the thin film made of an electron-emitting material, there is an effect of reducing variations in element formation, the electron emission amount of each electron source becomes uniform, and the quality of image display is improved. Can be improved.

[Brief description of drawings]

1A and 1B are a plan view and a cross-sectional view of an electron source material showing an example of the present invention.

FIG. 2 is a plan view and a cross-sectional view showing another example of the electron source material of the present invention.

FIG. 3 is a basic manufacturing method diagram of the electron source of the present invention.

FIG. 4 is a diagram showing a voltage waveform of a forming process.

FIG. 5 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring electron emission characteristics.

FIG. 6 shows an emission current I _{e, a} device current I _f, and a device voltage V _f.
The figure which shows the typical example of.

7A and 7B are a plan view and a cross-sectional view showing another example of the electron source of the present invention.

FIG. 8 is a perspective view of a display device configured using the electron source of the present invention.

FIG. 9 is a plan view and a sectional view of a conventional electron source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electron emission part forming thin film 3 Electron emission part 4 Thin film including electron emission part 5 Element electrode 6 Heat defective conductor 7 Power feeding point 30 Ammeter 31 Power supply 32 Ammeter 33 Power supply 34 Anode electrode 72 X direction wiring 73 Y-direction wiring 74 Electron source 81 Rear plate on which the electron source is fixed 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate

Claims (5)

[Claims] 1. An electron source material having a device electrode and a thin film made of an electron emitting material, wherein a poor heat conductor is interposed at least at a part of an interface between the device electrode and the thin film. material. 2. The electron source material according to claim 1, wherein a power feeding portion is formed in a portion near a center of the thin film made of the electron emitting material. 3. A method of manufacturing an electron source, wherein an energization process is performed so that a voltage is applied between the element electrodes of the electron source material according to claim 1 in a vacuum atmosphere. 4. An electron source manufactured by the method of claim 3. 5. An image forming apparatus incorporating the electron source according to claim 4.