JPH07192605A - Electron source and image forming device - Google Patents

Abstract

PURPOSE:To provide a highly fine large image plane having an electron source constituted by using a surface conduction type emitting element. CONSTITUTION:An X directional wiring electrode 12 is buried in a recessed groove formed in an insulating substrate 11, and a Y directional wiring electrode 14 is buried in a recessed groove formed in an insulator layer 13 laminated on this electrode 12. An electron source, integrally formed with many surface conduction type emitting elements connected to XY matrix wiring constituted of these electrodes, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source and an image forming apparatus such as a display device which is an application thereof, and more particularly to an electron source including a large number of surface conduction electron-emitting devices and an image of a display device which is an application thereof. The present invention relates to a novel structure of a forming device.

[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 type emission element (hereinafter abbreviated as SCE), and the like.

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. S
pindt, "PHYSICAL Properties"
of thin-film field emiss
ion Cathodes with molly bd
enium cones ", J. Appl. Phy
s. , 47, 5248 (1976) and the like are known.

An example of the MIM type is C.I. A. Mea
d, "The tunnel-emission am
plier ", J. Appl. Phys., 32,
646 (1961) and the like are known.

As an example of the SCE type, M. I. Elin
son, Radio Eng. Electron Ph
ys. , 10, (1965) and so on.

The SCE type utilizes a phenomenon in which electron emission occurs when a current is passed through 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 Elinson et al., One using the Au thin film [G. Dittme
r: "Thin Solid Films", 9, 31
7 (1972)], by In ₂ O ₃ / SnO ₂ thin film [M. Hartwellland C. G. Fonsta
d: "IEEE Trans.ED Conf.", 5
19 (1975)], by a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)].
Etc. have been reported. As a typical device configuration of these surface conduction electron-emitting devices, M. The Hartwell gene structure is shown in FIG. In the figure, 1 is an insulating substrate.
2 is a thin film for forming an electron emitting portion, which has an H-shaped pattern,
The electron emitting portion 3 is made of a metal oxide thin film formed by sputtering and is subjected to an energization process called forming, which will be described later.
Is formed. 4 will be referred to as a thin film including an electron emitting portion. In the figure, L1 is 0.5 to 1 mm and W is 0.1 m.
It is set in m.

Conventionally, in these surface conduction electron-emitting devices, it is general that the electron-emitting portion forming thin film 2 is previously formed with the electron-emitting portion 3 by an energization process called forming before the electron emission. . 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 2 to make it an electrically high resistance electron. That is, the emission part 3 is formed. 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 surface conduction electron-emitting device that has been subjected to the forming process is one in which electrons are emitted from the electron-emitting portion 3 by applying a voltage to the thin film 4 including the electron-emitting portion and passing a current through the element. However, in these conventional surface conduction electron-emitting devices,
Although there were various problems in practical application, the present applicants have earnestly studied various improvements as described below, and have solved various problems in practical application.

The above-described surface conduction electron-emitting device has an advantage that a large number of devices 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. For example,
Examples include a charged beam source and a display device. An example of an array of a large number of surface conduction electron-emitting devices is an electron source in which surface conduction electron-emitting devices are arranged in parallel and a plurality of rows in which both ends of each element are connected by wiring are arranged ( For example, Japanese Patent Laid-Open No. 1-031332 of the present applicant). In addition, particularly in image forming apparatuses such as display devices, in recent years,
Flat panel display devices using liquid crystal have become widespread instead of CRTs, but since they are not self-luminous, they have problems such as having a backlight, etc. Therefore, development of self-luminous display devices is desired. It has been rare. By the electron source with many surface conduction electron-emitting devices and the electrons emitted from the electron source,
An image forming apparatus, which is a display device in which a phosphor that emits visible light is combined, is a self-luminous display device that can be relatively easily manufactured even with a large screen device and has an excellent display portion (for example, the present application. USP 5066883).

[0009]

When a screen of a display device constituted by using an electron source in which a plurality of surface conduction electron-emitting devices are arranged is enlarged and electrically driven, drive wiring arranged in the screen. Becomes longer, and the wiring resistance corresponding to the wiring length increases between the wiring electrode ends opposite to the voltage-applied wiring electrode ends. This causes the following problems.

(1) A voltage drop occurs with respect to the applied voltage, and the voltage applied between the connecting elements at both ends of the wiring is different, resulting in a difference in display brightness, which causes image unevenness.

(2) A time delay of the applied element drive signal occurs, which causes a time lag of the drive signal applied between the connection elements at both ends of the wiring, resulting in image disturbance.

In order to solve such a problem, if the wiring width is widened to reduce the wiring resistance, the area of a corresponding one element in the screen becomes large and high-definition image display cannot be performed. On the other hand, in the case of increasing the height of the wiring to reduce the wiring resistance, it is necessary to increase the ratio of the height to the width of the wiring, that is, the aspect ratio. A pattern plating method using a plating resist is an effective method for manufacturing this high aspect ratio wiring, but the wiring obtained by the plating method is generally dense, and the thicker the film, the more it grows. Therefore, the internal stress of the plating film increases and the possibility of peeling from the substrate increases. Further, as for the thin film wiring or the printed wiring, the thicker the film thickness, the higher the possibility of peeling from the substrate or cracking of the wiring itself.

Further, even if a high aspect ratio wiring can be realized, the step difference which occurs in the case of the multilayer wiring structure has been an obstacle to the degree of freedom in designing the electron optical system when the area of the flat panel image display device is increased. .

In view of the above conventional problems, the present invention provides an electron source and an electron source for controlling an emitted electron amount by selecting an arbitrary element from an electron source composed of a large number of elements with a simple structure and easily. In an image forming apparatus such as a display device in which image forming members such as phosphors are arranged at opposing positions, it is an object of the present invention, in particular, to reduce the resistance of wiring electrodes and to obtain a higher quality image.

[0015]

SUMMARY OF THE INVENTION The present invention, which has been made to achieve the above object, has an electrode layer embedded in a recessed groove provided in an insulating substrate or an insulating layer on the substrate. An electron source characterized in that a surface conduction electron-emitting device is integrally formed on a substrate having the above structure, and further, an image forming apparatus equipped with the electron source.

In particular, according to the present invention, as will be described later in detail, since the wiring electrode is embedded in the base body, the wiring electrode can be easily thickened and a low resistance wiring can be realized. It is a thing.

In particular, the basic structure and manufacturing method of the surface conduction electron-emitting device according to the present invention by the present applicant and the characteristic thereof (for example, refer to JP-A-2-56822) will be outlined below.

The features of the structure and manufacturing method of the surface conduction electron-emitting device according to the present invention are as follows.

1) A thin film for forming an electron emission portion before energization treatment called forming is composed of a thin film of fine particles formed by dispersing a fine particle dispersion or fine particles formed by heating and burning an organic metal or the like. Basically, such as thin film,
Composed of fine particles.

2) The thin film including the electron emitting portion after the energization treatment called forming is basically composed of fine particles, both the electron emitting portion and the thin film including the electron emitting portion.

6 (a) and 6 (b) are a plan view and a sectional view, respectively, showing the structure of a basic surface conduction electron-emitting device according to the present invention. The basic structure of the device according to the present invention will be described with reference to FIG. 6. As will be described later in the electron source and the image forming apparatus of the present invention, a large number of surface conduction electron-emitting devices are formed on the same substrate. It is formed together with the wiring electrodes.

In FIG. 6, 1 is an insulating substrate, 5 and 6 are device electrodes, 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion.

As the insulating substrate 1, quartz glass, Na
Examples thereof include glass having a reduced content of impurities such as blue glass, soda lime glass, a glass substrate obtained by laminating SiO ₂ (insulator layer) formed on the soda lime glass by a sputtering method, and ceramics such as alumina.

Any material may be used as the material of the opposing device electrodes 5 and 6 as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Al, Cu, Pd and Pd, A
_{g, Au, RuO 2, Pd} -Ag or the like metal or metal oxide and printed conductor composed of glass or the like, In ₂ O ₃ -Sn
Examples thereof include transparent conductors such as O ₂ and semiconductor materials such as polysilicon. The element electrode spacing L1 is several hundreds of angstroms to several hundreds of micrometers, and is based on the photolithography technology that is the basis of the manufacturing method of the element electrodes, that is, the performance of the exposure device and the etching method, and the voltage applied between the element electrodes. It is set depending on the electric field strength capable of emitting electrons, etc., but is preferably 1 micrometer to 10 micrometers. The element electrode length W1, the film thickness d of the element electrodes 5 and 6 are the resistance value of the electrode, the connection with the X and Y wirings described above,
The device electrode length W1 is normally designed to be several hundreds of micrometers to several hundreds of micrometers, and the film thickness d of the device electrodes 5 and 6 is preferably designed in consideration of the layout problem of a large number of electron sources. , Hundreds of angstroms and a few micrometers.

The thin film 4 including the electron emitting portion provided between the device electrodes 5 and 6 facing each other provided on the insulating substrate 1 and on the device electrodes 5 and 6 includes the electron emitting portion 3,
Not only the case shown in FIG. 6B, but also the device electrodes 5, 6
It may not be installed on the top. That is, it is a case where the above-described thin film for forming an electron emission portion and the opposing device electrodes 5 and 6 are laminated in this order on the insulating substrate 1. Further, depending on the manufacturing method, the entire space between the opposing device electrodes 5 and 6 may function as an electron emitting portion. The film thickness of the thin film 4 including the electron emitting portion is several angstroms to several thousand angstroms, preferably 10 angstroms to 200 angstroms, the step coverage to the device electrodes 5 and 6, the electron emitting part 3 and the device electrode 5 , 6 between them, the particle size of the conductive fine particles of the electron emission portion 3, the energization processing conditions described later, and the like. The resistance value is 10 7 to 10 7 ohm /
The sheet resistance value of □ is shown. Specific examples of the material forming the thin film 4 including the electron emitting portion are Pd, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
a, W, Pb and other metals, PdO, SnO ₂ , In ₂ O ₃ ,
Oxides such as PbO and Sb ₂ O ₃ , HfB ₂ , ZrB ₂ and La
Borides of B ₆ , CeB ₆ , YB ₄ , GdB _4, etc., TiC, Z
Carbides such as rC, HfC, TaC, SiC, WC, Ti
Nitride such as N, ZrN and HfN, semiconductor such as Si and Ge, carbon, AgMg, NiCu, Pb, Sn and the like, which are formed of a fine particle film.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which the fine particles are individually dispersed but also in a state in which the fine particles are adjacent to each other or overlap each other (islands). (Including the shape).

The electron emitting portion 3 is composed of a large number of conductive fine particles having a particle diameter of several angstroms to several thousand angstroms, preferably 10 angstroms to 200 angstroms. The thickness depends on the film thickness of the thin film 4 including the electron emitting portion and the manufacturing method such as energization processing conditions described later and is appropriately set. The material forming the electron emitting portion 3 is the same as some or all of the elements of the material forming the thin film 4 including the electron emitting portion.

Various methods are conceivable as a method of manufacturing an electron-emitting device having the electron-emitting portion 3, one example of which is shown in FIG. Reference numeral 2 is a thin film for forming an electron emitting portion, and for example, a fine particle film can be mentioned.

The manufacturing method will be described below step by step with reference to FIGS. 6 and 7.

1) After the insulating substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like, and then on the surface of the insulating substrate 1 by a photolithography technique. Element electrodes 5 and 6 are formed on the substrate (FIG. 7A).

2) Between the device electrodes 5 and 6 provided on the insulating substrate 1, an organic metal solution is applied on the insulating substrate on which the device electrodes 5 and 6 are formed, and the substrate is left to stand. , Forming an organometallic thin film. The organic metal 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, etc. to form the electron-emitting portion forming thin film 2 (FIG. 7B). Here, the description has been given by using the coating method of the organometallic solution, but the application method is not limited to this, and the vacuum deposition method,
It may be formed by a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like.

3) Subsequently, when an energization process called forming is performed by applying a pulsed voltage between the device electrodes 5 and 6 by a power source (not shown), the structure of the electron emission part forming thin film 2 changes in structure. The electron emission part 3 is formed (FIG. 7).
(C)). By this energization process, the electron emission portion forming thin film 2
Is locally destroyed, deformed, or altered, and the site where the structure is changed is called an electron emitting portion 3. As I explained earlier,
The applicants have observed that the electron emitting portion 3 is composed of conductive fine particles.

FIG. 8 shows an example of the voltage waveform of the forming process.

In FIG. 8, T1 and T2 are the pulse width and pulse interval of the voltage waveform. T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (during forming) Peak voltage of 4V-10
V is set to about V, and the forming process is appropriately set in a vacuum atmosphere for about several tens of seconds.

When forming the electron emitting portion described above,
Although the forming process is performed by applying a triangular wave pulse between the electrodes of the element, the waveform applied between the electrodes of the element is not limited to the triangular wave, and a desired waveform such as a rectangular wave may be used. The high value, the pulse width, the pulse interval, and the like are not limited to the above values, and a desired value can be selected as long as the electron emitting portion is well formed.

FIG. 9 is a schematic block diagram of a measurement / evaluation apparatus for measuring electron emission characteristics of the electron-emitting device according to the present invention having the configuration shown in FIG. In FIG. 9, 1
Is an insulating substrate, 5 and 6 are device electrodes, 4 is a thin film including an electron emitting portion, and 3 is an electron emitting portion. Further, 91 is a power supply for applying the element voltage Vf to the element, and 90 is the element electrode 5.
Device current If flowing through the thin film 4 including the electron emission portion between 6
For measuring the current, 94 is an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device, 93 is a high voltage power supply for applying a voltage to the anode electrode 94, and 92 is the electron of the device. It is an ammeter for measuring the emission current Ie emitted from the emission unit 3. In measuring the device current If and the emission current Ie of the electron-emitting device, a power supply 91 and an ammeter 90 are connected to the device electrodes 5 and 6, and a power supply 94 and an ammeter 92 are connected above the electron-emitting device. The anode electrode 94 is disposed. Further, the electron-emitting device and the anode electrode 94 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 device can be measured and evaluated.

The voltage of the anode electrode is 1 kV to 10 kV.
kV, the distance H between the anode electrode and the electron-emitting device is 3 mm
It was measured in the range of ~ 8 mm.

In the surface conduction electron-emitting device, a part of the basic manufacturing method for the basic device structure may be modified.

Next, the electron source and the image forming apparatus of the present invention will be described with reference to FIG. 111 is an insulating substrate, 112 is X-direction wiring, 113 is Y-direction wiring, 114
Is a surface conduction electron-emitting device, and 115 is a wire connection.

In the figure, the insulating substrate 111 is the above-mentioned glass substrate or the like, and its size and its thickness are
To maintain the number of surface conduction electron-emitting devices installed on the insulating substrate 111 and the designed shape of each device, and to hold the containers in a vacuum when forming a part of the container when the electron source is used. It is set as appropriate depending on the conditions, etc. The m wirings in the X direction 112 are made of DX ₁ , DX ₂ , ..., DX _m , and are formed on the insulating substrate 111 by a vacuum vapor deposition method, a printing method, a sputtering method, or the like to have a desired pattern of conductivity. The material, the film thickness, and the wiring width are set so that a large number of surface conduction electron-emitting devices can be supplied with a voltage that is as substantially uniform as possible. The Y-direction wiring 113 includes DY ₁ , DY _2, ... DY
_{It is composed} of n wirings of n, is formed by a vacuum evaporation method, a printing method, a sputtering method or the like like the X-direction wiring 112, and is made of a conductive metal or the like having a desired pattern. The material, film thickness, wiring width, etc. are set so that a substantially uniform voltage is supplied. These m wirings in X direction 1
An interlayer insulating layer (not shown) is provided between the 12 and n Y-direction wirings 113 and electrically separated to form a matrix wiring. In addition, both m and n are positive integers. The interlayer insulating layer (not shown) is SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method or the like, and the X-direction wiring 1
12 is formed on the entire surface or a part of the insulating substrate 111 having a desired shape, and in particular, the film thickness, material, and manufacturing method are set so as to withstand the potential difference at the intersection of the X-direction wiring 112 and the Y-direction wiring 113. Is set appropriately. Also, the X-direction wiring 112
And the Y-direction wiring 113 are drawn out as external terminals.

Although an example in which n Y-direction wirings 113 are provided on the m X-direction wirings 112 via an interlayer insulating layer has been described, m wirings are provided on the n Y-direction wirings 113. In some cases, the X-direction wiring 142 is installed via an interlayer insulating layer.

Further, in the same manner as described above, the device electrodes (not shown) of the surface conduction electron-emitting device 114 facing each other have m X electrodes.
Direction wirings DX ₁ , DX ₂ , ... DX _m , m wirings and X direction wirings 112, DY ₁ , DY ₂ , ..., DY _n , n wirings Y direction 113, vacuum evaporation method, printing method, sputtering They are electrically connected by a connecting wire 115 made of a conductive metal or the like formed by a method or the like.

The m wirings in the X direction 112, the n wirings in the Y direction 113, the connection wires 115, and the conductive metal of the device electrodes are
Some or all of the constituent elements may be the same or different, and Ni, Cr, Au, Mo,
A printed conductor composed of a metal or alloy such as W, Pt, Ti, Al, Cu and Pd and a metal or metal oxide such as Pd, Ag, Au, RuO ₂ , Pd-Ag and glass, and In.
It is appropriately selected from a transparent conductor such as ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon. The surface conduction electron-emitting device may be formed either on the insulating substrate 111 or on an interlayer insulating layer (not shown).

The X-direction wiring 112 is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for arbitrarily scanning a row of surface conduction electron-emitting devices 114 arranged in the X-direction. It is connected to the.

On the other hand, a modulation signal generating means (not shown) for applying a modulation signal for arbitrarily modulating each row of the surface conduction electron-emitting devices 114 arranged in the Y direction to the Y-direction wiring 113. It is electrically connected.

Further, the drive voltage applied to each surface conduction electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

Next, an image forming apparatus using the electron source created as described above for display and the like will be described with reference to FIGS. 3 and 4. FIG. 3 is a basic configuration diagram of the image forming apparatus, and FIG. 4 is a pattern of a fluorescent film used in the image forming apparatus. 31 is an electron source substrate on which the electron-emitting device is manufactured as described above, 32 is a rear plate to which the electron source substrate 31 is fixed, 40 is a face on which a fluorescent film 38 on the inner surface of a glass substrate 37, a metal back 39 and the like are formed. Plates 33 are support frames, and the rear plate 32 and the face plate 40 are sealed with frit glass or the like to form the envelope 41.

The envelope 41 is composed of the face plate 40, the support frame 33, and the rear plate 32 as described above.
Since the rear plate 32 is provided mainly for the purpose of reinforcing the strength of the substrate 31, if the substrate 31 itself has sufficient strength, the separate rear plate 32 is not necessary, and the support frame 33 is directly sealed to the substrate 31. Then, the face plate 40, the support frame 33, and the substrate 31 may constitute the envelope 41.

In the case of monochrome, the fluorescent film 38 is composed of only a fluorescent substance, but in the case of a color fluorescent film, a black conductive material called a black stripe or a black matrix depending on the arrangement of fluorescent substances as shown in FIG. Four
2 and the phosphor 43. Black stripes,
The purpose of providing the black matrix is to make the mixed colors of the three primary color phosphors, which are necessary for color display, different from each other by making the portions of the three phosphors 43 differently colored, and to reflect external light on the phosphor film 38. This is to suppress the decrease in contrast due to. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, but is not limited to this as long as it is a material having conductivity and little light transmission and reflection.

As a method for applying the phosphor to the glass substrate 37, a precipitation method or a printing method is used regardless of monochrome or color.

A metal back 39 is usually provided on the inner surface of the fluorescent film 38. The purpose of the metal back is to improve the brightness by specularly reflecting the light to the inner surface side of the light emitted from the phosphor to the face plate 40 side, to act as an electrode for applying an electron beam acceleration voltage, and This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. The metal back can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like. The face plate 40 further includes a fluorescent film 38 in order to further increase the conductivity of the fluorescent film 38.
A transparent electrode (not shown) may be provided on the outer surface side of the.

When performing the above-mentioned sealing, in the case of color, it is necessary to sufficiently align the phosphors of the respective colors with the electron-emitting devices.

The envelope 41 is connected to an exhaust pipe (not shown) and
The degree of vacuum is set to about 0 to the 6th power [Torr], and the envelope 41 is sealed.

The terminals Dx _{1 to} Dxm and Dy _{1 to} D outside the container
A voltage is applied between the opposing device electrodes through yn, and the above-mentioned forming is performed to form an electron-emitting portion to manufacture an electron-emitting device. In addition, a getter process may be performed in order to maintain the degree of vacuum after the envelope 41 is sealed. this is,
Immediately before or after sealing the envelope 41, a getter arranged at a predetermined position (not shown) in the envelope 41 is heated by a heating method such as resistance heating or high-frequency heating to form a vapor deposition film. Is a process for forming. Getter is usually Ba
Etc. are the main components, and the degree of vacuum of, for example, 1 × 10 −5 or 1 × 10 −7 [Torr] is maintained by the adsorption action of the vapor deposition film.

In the image display device of the present invention completed as described above, each of the electron-emitting devices has a terminal Dx ₁ -outside the container.
Electrons are emitted by applying a voltage through Dxm, Dy _{1 to} Dyn, and a high voltage of several kV or more is applied to the metal back 39 or the transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam. The image is displayed by colliding with the fluorescent film 38 to excite and emit light.

The configuration described above is a schematic configuration necessary for producing a suitable image forming apparatus used for image display and the like, and the detailed parts such as the material of each member are not limited to the above contents. Instead, it is appropriately selected to suit the application of the image forming apparatus.

Further, according to the concept of the present invention, the light emitting diode is not limited to a suitable image forming apparatus used for displaying an image, but an alternative light emitting diode such as a light emitting diode of an optical printer including a photosensitive drum and a light emitting diode is used. The image forming apparatus described above can also be used as a source. At this time, the above-mentioned m
By properly selecting one row-direction wiring and n column-direction wiring, it can be applied not only as a line-shaped light emitting source but also as a two-dimensional light-emitting source.

Next, the surface conduction electron-emitting device having the above-mentioned characteristics is integrally formed on the substrate having the structure in which the electrode layer (wiring electrode) is embedded in the recessed groove which is a feature of the present invention. An example will be described.

FIG. 1 shows one embodiment of a substrate according to the electron source of the present invention. FIG. 1 (a) is a partial plan view and FIG.
1B is a sectional view taken along the line AA ′ of FIG. 1A, and FIG. 1C is a sectional view taken along the line BB ′ of FIG.

In this embodiment, a large number of surface conduction electron-emitting devices are arranged in matrix in a matrix. this is,
First, a concave groove for forming an X-direction wiring electrode is directly formed on the insulating substrate 11.

Next, the wiring electrode material is filled in the recesses to obtain the X-direction wiring electrode 12 in the insulating substrate 11.

Next, the insulator layer 13 is formed on the entire surface of the substrate.

Subsequently, a contact hole 1 for connecting to the element electrode 5 is formed in the insulator layer 13 on the X-direction wiring electrode 12.
Open 5 '.

Further, a concave groove for forming the Y-direction wiring electrode 14 is formed in the insulator layer 13.

Further, the wiring electrode material is filled in the contact hole 15 ′ formed in the insulating layer 13 and the concave groove for forming the Y-direction wiring electrode to obtain the connection 15 and the Y-direction wiring electrode 14 in the insulating layer 13. .

As described above, the device electrodes 5 and 6 of the surface conduction electron-emitting device are connected to the Y-direction wiring electrode 14 and the wire connection 15, respectively, on the substrate in which the X-direction and Y-direction wiring electrodes are embedded. Then, the surface conduction electron-emitting device is integrally formed by the above-described method for manufacturing the device.

In the present invention, the depth of the recessed groove is basically not limited, but generally, if the depth is not less than the thickness for forming a thin film, that is, about 10 μm or more, the wiring thickness is smaller than that of the thin film method. The thickness can be increased, and an effect as a low resistance wiring is produced.

In a wiring such as a liquid crystal display device (LCD), since the cell thickness of TN liquid crystal is about 7 μm, generally a wiring having a thickness of 10 μm cannot exist on the substrate. That is, there arises a problem that the cell thickness cannot be controlled. Since the wiring according to the present invention is embedded in the substrate,
Even when used in these display devices, it is effective because it can be formed as a sufficiently low resistance wiring.

The method for processing the recessed groove is not particularly limited, but for example, a mechanical cutting method using a dicing saw, which is generally well known, or other mechanical cutting method, or a compression method using a die press. Etc. can be used.

As a method of forming the wiring electrode,
A plating method for forming a plating film, a blade coating method using a conductive paste, or the like can be used. When a conductive paste is used as the wiring electrode material, the firing temperature of the conductive paste is 550 ° C. to 6 when the substrate is a glass material.
Recommended in the range of 00 ° C.

The dimensions and thickness of the insulating layer are not particularly limited as long as they are sufficiently insulated in terms of electric driving. When an insulating glass paste is used as the insulating layer, it can be formed by screen printing or dip coating.

The electron source of the present invention having the above-described structure and the image forming apparatus equipped with the electron source have a buried structure, so that each wiring electrode can be made thick and low resistance wiring can be realized. Further, since the wiring shape can be controlled by the concave groove processing accuracy, there is an advantage that the dimensional accuracy of each wiring is improved. Generally, in screen printing and the like, it is difficult to precisely control the absolute dimensional accuracy of printed wiring due to screen elongation, paste flow, and the like.

Further, since each wiring and the insulating layer are formed in a flat state, there is no problem that the insulating layer is thinly formed at the edge portion of the lower electrode in the multilayer wiring structure and dielectric breakdown occurs at that portion. . Further, since there is no step on the film surface to be laminated, there is an advantage that problems such as step breakage do not occur. Furthermore, since the structure on the surface of the substrate is simplified, there are no various obstacles that occur when the area is increased, and the degree of freedom in designing the electron optical system is expanded.

Further, according to the configuration of the present invention, a large number of elements can be easily arranged in an XY matrix, and a large-screen image display device can be provided. Although the recessed groove is filled with the X-direction wiring electrode 12 and the Y-direction wiring electrode 14 in FIG. 1, the present invention is not limited to this, and only one wiring electrode may be filled into the recessed groove.

[0075]

EXAMPLES Next, examples of the present invention will be described.

Example 1 In this example, an electron source substrate having the structure shown in FIG. 1 was prepared, and an image forming apparatus was prepared by using the electron source substrate.

First, 40 cm Corner, thickness about 3mm
The insulating substrate 11 made of soda lime glass was thoroughly washed.
After that, the concave groove for forming the X-direction wiring electrode 12 is cut off.
It was formed directly on the edge substrate 11. Groove formation is generally good
Known dicing saw (trade name Disco Cutter: Di
SCO). In this embodiment, this X-direction
The line electrode forming recess has a width of 100 μm and a depth of 100 μm.
did.

Next, a silver paste which is a wiring electrode material is used to fill the recesses formed in the insulating substrate 11 using a blade coater. Further, it was baked at about 580 ° C. for 15 minutes to obtain the X-direction wiring electrode 12 in the insulating substrate 11.

Next, an insulating glass paste is printed on the entire surface of the substrate by screen printing, and the paste is applied at about 580 ° C. for 15 minutes.
It was baked for minutes to form an insulator layer 13. Insulator layer 1 at this time
The thickness of 3 was 80 μm.

Subsequently, a contact hole 1 for connecting to the element electrode 6 is formed in the insulator layer 13 on the X-direction wiring electrode 12.
Open 5'and then Y in the direction that intersects the X direction wiring electrode.
A concave groove for forming the directional wiring electrode 14 was formed in the insulator layer 13 with a dicing saw. The recess for Y-direction wiring electrode formation had a width of 100 μm and a depth of 60 μm.

Further, a silver paste, which is a wiring electrode material, was simultaneously filled in the contact hole formed in the insulator layer 13 and the concave groove for forming the Y-direction wiring electrode by using a blade coater. Further, it was baked at about 580 ° C. for 15 minutes to obtain a wire 15 and a Y-direction wiring electrode 14 in the insulator layer 13.

The thus formed X, Y matrix-shaped embedded wiring electrodes are continuous and flat films, and the resistivity thereof is about 1 mΩ / □ or less at a film thickness of 100 μm, which is a sufficiently low resistance. It was The embedded state was also good.

Further, in the case where the gold plating film by the plating method is used as the electrode forming method in the present embodiment, first, Ni is formed by vacuum film formation on the entire surface of the substrate in which the concave groove is formed first.
The film was formed on the entire surface, and the unnecessary Ni film other than the concave groove was removed by photolithography and etching. Then Ni
Was used as an electrode to perform electrolytic plating to form an Au electrode.

The embedded electrode formed by the plating method as described above also has a resistivity of about 1 mΩ / at a film thickness of 100 μm.
□ The resistance was sufficiently low as below.

Subsequently, the surface conduction electron-emitting device as shown in FIG. 6 is formed by the photolithography technique and the etching technique.

First, a pattern to form the device electrodes 5 and 6 and the gap between the device electrodes is formed by a photoresist (RD-2000).
N-41 manufactured by Hitachi Chemical Co., Ltd.) and formed by a vacuum vapor deposition method.
Ti with a thickness of 50Å and Ni with a thickness of 1000Å were sequentially deposited. Dissolve the photoresist pattern with an organic solvent and remove Ni /
The Ti deposition film was lifted off, the device electrode interval L ₁ was set to 3 μm, and the device electrodes 5 and 6 having the device electrode width W ₁ of 300 μm were formed.

Next, as shown in FIG. 11, a Cr film having a film thickness of 1000 Å is deposited and patterned by vacuum evaporation using a mask having an inter-element electrode gap L ₁ and an opening in the vicinity thereof, and organopalladium (ccp423) is formed on the Cr film.
0 Okuno Pharmaceutical Co., Ltd.) spin coated with a spinner,
It was heated and baked at 300 ° C. for 10 minutes. Further, the film thickness of the electron-emitting-portion-forming thin film 2 formed of fine particles of palladium as the main element thus formed was 100Å, 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, the Cr film and the thin film 2 for forming an electron emission portion after firing were etched by an acid etchant to form a desired pattern.

Next, an example in which an image forming apparatus is configured by using the electron source substrate created as described above will be described with reference to FIGS.
Will be explained.

After fixing the electron source substrate 31 on which a large number of surface conduction electron-emitting devices have been formed as described above on the rear plate 32, the face plate 40 (fluorescent on the inner surface of the glass substrate 37) is placed 5 mm above the substrate 31. (A film 38 and a metal back 39 are formed) are arranged via a support frame 33, and frit glass is applied to the joint portion of the face plate 40, the support frame 33, and the rear plate 32 in the atmosphere or nitrogen atmosphere. It was sealed by baking at 400 ° C. to 500 ° C. for 10 minutes or more (see FIG. 3). The frit glass was also used to fix the substrate 31 to the rear plate 32.

In FIG. 3, 34 is an electron-emitting device and 3
Reference numerals 5 and 36 denote wirings in the X direction and the Y direction, respectively.

In the case of monochrome, the fluorescent film 38 is made of only the fluorescent material, but in this embodiment, the fluorescent material adopts a stripe shape (see FIG. 4), a black stripe is first formed, and each space is formed in the gap. A phosphor was applied to form a phosphor film 38. As a material for the black stripe, a material containing graphite as a main component, which is often used, was used.

The method of applying the phosphor to the glass substrate 37 was the slurry method.

A metal back 39 is usually provided on the inner surface side of the fluorescent film 38. 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 40 is further provided with a fluorescent film 3
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 38 in order to enhance the conductivity of No. 8, but in this embodiment, it was omitted because sufficient conductivity was obtained only by the metal back.

At the time of 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 D _{X1 to} D _Xm and D _A voltage was applied between the device electrodes of the electron-emitting device 34 through _{Y1 to} D _Yn , and the electron-emitting region forming thin film 2 was energized (forming process) to form the electron-emitting region 3.
FIG. 8 shows the voltage waveform of the forming process.

In FIG. 8, T ₁ and T ₂ are the pulse width and the pulse interval of the voltage waveform. In this embodiment, T ₁ is 1 millisecond and T _{2 is}
Is 10 milliseconds, the peak value of the triangular wave (peak voltage during forming) is 5 V, and the forming process is about 1 × 1.
It was carried out for 60 seconds in a vacuum atmosphere of 0 minus 6 torr.

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 30Å.

Next, an exhaust pipe (not shown) was heated by a gas burner at a vacuum degree of about 10 <-6> [Torr] to weld and seal the envelope.

Finally, in order to maintain the degree of vacuum after sealing,
Getter processing was performed. Immediately before sealing, a getter arranged 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.

In the image display device of the present invention completed as described above, each of the electron-emitting devices has terminals D _{X1 to} D _X outside the container.
Electrons are emitted by applying a scanning signal and a modulation signal through _Xm and D _{Y1 to} D _Yn respectively by a signal generating means (not shown), and a high voltage of several kV or more is applied to the metal back 39 through a high voltage terminal Hv. An image was displayed by accelerating the electron beam, causing it to collide with the fluorescent film 38, and exciting and emitting light.

As described above, according to the electron source composed of the buried electrode according to the present embodiment, each wiring electrode can be thickened and the low resistance wiring can be realized by adopting the buried structure. Further, the wiring shape can be controlled by the processing accuracy of the recessed groove, and the dimensional accuracy of each wiring is improved.

Furthermore, since each wiring and insulating layer are formed in a flat state, dielectric breakdown does not occur at the edge portion of the lower electrode, which is a problem in the multilayer wiring structure. Further, since there is no step on the film surface to be laminated, there is no problem such as step breakage. Further, in the electron source and the image forming apparatus of the present embodiment according to the present invention, the surface shape of the electron source substrate is simplified, there are no various obstacles that occur when the area is increased, and the degree of freedom in instrumentation of the electron optical system is high. Expands.

Further, according to the structure of this embodiment, a large number of surface conduction electron-emitting devices can be easily arranged in an X, Y matrix, which is suitable for the production of a large-screen image forming apparatus.

Example 2 In this example, an electron source substrate having a structure as shown in FIG. 2 was produced, and an image forming apparatus was produced using this.

2 (a) is a partial plan view of the electron source substrate, and FIG. 2 (b) is a sectional view taken along the line AA 'of FIG. 2 (a).

First, 40 cm Corner, thickness about 3mm
The insulating substrate 21 made of soda-lime glass was thoroughly washed.
After that, the concave groove for forming the line wiring electrode 22 is cut off.
It was formed directly on the edge substrate 21. The groove is formed in Example 1
Done by law.

Next, a silver paste, which is a wiring electrode material, is filled in the concave groove formed in the insulating substrate 21 using a blade coater. Furthermore, the line wiring electrode 22 was obtained in the insulating substrate 21 by baking at about 580 ° C. for 15 minutes.

The buried electrode of the line wiring thus formed could have a sufficiently low resistance as in the first embodiment.

Also, when a gold plating film formed by a plating method was used as the electrode forming method, the resistance could be made sufficiently low as in Example 1.

Subsequently, the surface conduction electron-emitting device as shown in FIG. 6 is formed by the photolithography technique and the etching technique in the same manner as in Example 1 so that the device electrodes 5 and 6 are connected to the line wiring electrode 22. It was formed.

Next, the electron source substrate produced as described above was subjected to a forming treatment in the same manner as in Example 1.

In the electron source of this structure, a plurality of strip-shaped wirings are arranged in the electron-emitting portion in a plane shape, and a plurality of strip-shaped grid electrodes having openings are arranged above the electron-emitting portions so as to be orthogonal to the wirings. By controlling the drive voltage applied to the electron-emitting device wiring and the grid electrode, electrons can be emitted from any electron-emitting device.

Further, as in the first embodiment, a plurality of electron sources of this embodiment are arranged in a vacuum container, face plates are opposed to each other, and the phosphor is selectively irradiated with the electron beam emitted from the electron-emitting device. As a result, the phosphor was made to emit light, whereby an image forming apparatus could be obtained.

As described above, according to the electron source composed of the buried electrode according to the present embodiment, the buried wiring structure can increase the thickness of the line wiring electrode and realize the low resistance wiring. Further, the dimensional accuracy of each wiring is determined by the concave groove machining accuracy, and the dimensional accuracy of each wiring is improved.

Further, in this embodiment, since the line wiring electrode is embedded in the insulating substrate, it is not necessary to provide an insulating layer, and since there is no step, the flatness is excellent.

In addition, in the electron source and the image forming apparatus of this embodiment, the surface shape of the electron source substrate is simplified, there are no various obstacles that occur when the area is increased, and the degree of freedom in designing the electron optical system is high. Expands. Further, a large number of surface conduction electron-emitting devices can be easily arranged in a line, which is suitable for manufacturing a large-screen image forming apparatus.

Further, as an application of the present invention, an array-like light emitting element having a length of 40 cm is prepared by the method of forming an electron source of the above-mentioned Embodiments 1 and 2 and is arranged on a photosensitive drum to obtain an electrophotographic image. The recording device could be constructed.

Further, similar effects can be obtained even when the array light emitting elements are manufactured in the electrophotographic recording device.

[0121]

As described above, the present invention has the following effects.

(1) Since the wiring electrodes can be formed accurately and easily with a large thickness and a low resistance wiring can be realized, an image due to an increase in wiring resistance, which has been a problem when the area of an image forming apparatus or the like is enlarged, is obtained. It is possible to prevent the occurrence of unevenness and obtain an image forming apparatus with a high definition and large screen.

(2) The structure of the surface of the electron source substrate is simplified and flattened, and the dielectric breakdown, which has been a problem in the multilayer wiring structure, can be eliminated, so that the degree of freedom in designing the electron optical system can be increased. A large-screen image forming apparatus with high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electron source substrate formed by XY matrix wiring in a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an electron source substrate formed by line wiring in Example 2 of the present invention.

FIG. 3 is a partially cutaway perspective view showing a configuration example of an image forming apparatus according to the present invention.

FIG. 4 is a diagram showing a configuration example of a fluorescent film in the image forming apparatus according to the present invention.

FIG. 5 is a configuration diagram showing an example of a surface conduction electron-emitting device.

FIG. 6 is a schematic configuration diagram showing an embodiment example of a surface conduction electron-emitting device according to the present invention.

FIG. 7 is a schematic cross-sectional view showing an example of a method of manufacturing a surface conduction electron-emitting device according to the present invention.

FIG. 8 is an example of a voltage waveform of energization forming of the surface conduction electron-emitting device.

FIG. 9 is a schematic configuration diagram showing an apparatus for measuring and evaluating electron emission characteristics of a surface conduction electron-emitting device.

FIG. 10 is a schematic view of an electron source substrate configured by simple matrix wiring of a large number of surface conduction electron-emitting devices.

FIG. 11 is a plan view of an element involved in the manufacturing process of the electron source of the present invention.

[Explanation of symbols]

 11 Insulating Substrate 12 X Direction Wiring Electrode 13 Insulator Layer 14 Y Direction Wiring Electrode 15 Connection 15 'Contact Hole 21 Insulating Substrate 22 Line Wiring Electrode 31 Electron Source Substrate 32 Rear Plate 33 Support Frame 34 Electron Emitting Element 35 Row Direction Wiring 36 Directional Wiring 37 Glass Substrate 38 Fluorescent Film 39 Metal Back 40 Face Plate 41 Envelope 42 Black Conductive Material 43 Fluorescent Material 1 Insulating Substrate 2 Electron Emitting Part Forming Thin Film 3 Electron Emitting Part 4 Thin Film Including Electron Emitting Part 5 Element electrode 6 Element electrode 90 Ammeter 91 Power source 92 Ammeter 93 High voltage power source 94 Anode electrode 111 Insulating substrate 112 X direction wiring 113 Y direction wiring 114 Surface conduction type emission element 115 Connection

Claims (5)

[Claims] 1. A structure in which a surface conduction electron-emitting device is integrally formed on a substrate having a structure in which an electrode layer is embedded in a recessed groove provided in an insulating substrate or an insulating layer on the substrate. An electron source characterized by. 2. The electron source according to claim 1, wherein the recessed groove is formed by using a mechanical cutting method or a compression method. 3. The electron source according to claim 1, wherein the electrode material is a plating film or a conductive paste. 4. The electrode layer is formed by using a plating method or a blade coating method.
The electron source described in. 5. An image forming apparatus comprising the electron source according to claim 1.