JPH09245694A - Electron-source substrate, its manufacture, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron-source substrate in which a positioning margin for the process of forming an interlayer insulating layer is large enough to reduce the time for the process. SOLUTION: In a matrix wiring board on the surface of which first wiring 2 and second wiring 4 that cross almost at right angles via an interlayer insulating layer 3 are formed, a pair of roughly trapezoidal element electrodes 1, 1 connected to the first 2 and second 4 wiring are formed in the regions of the matrix wiring board which are surrounded by the first 2 and second 4 wiring. An electron emitting part is formed in the microclearance 5 between the pair of element electrodes 1, 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source substrate, particularly an electron source substrate having a plurality of surface conduction electron-emitting devices arranged on a two-dimensional plane, a method for manufacturing the same, and an image display incorporating the electron source substrate. Regarding the device.

[0002]

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

As an example of the FE type, WPDyke & WWDol
an, “Field emission”, Advancein Electron Physici
s, 8, 89 (1956) or CASpindt, “Physical Proper
ties of thin-film field emission cathodes with mol
ybdenum ”, J.Appl.Phys., 47, 5248 (1976) are known.

As an example of the MIM type, CAMead, “The
tunnel-emission amplifier, J. Appl. Phys., 32, 646
(1961) is known.

As an example of the surface conduction electron-emitting device, M.
I. Elinson, Radio Eng. Electron Phys., 10, (1965)]
Etc.

The surface conduction electron-emitting device 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. Examples of the surface conduction electron-emitting device include a device using a SnO ₂ thin film by Elinson et al., And a device using an Au thin film [G.
Dittmer: “Thin Solid Films”, 9, 317 (1972)], In ₂
O ₃ / SnO ₂ thin film [M.Hartwell and CG
Fonstad: “IEEE Trans. ED Conf.”, 519 (1975)], a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, page 22 (1983)] and the like are reported.

As a typical device configuration of these surface conduction electron-emitting devices, the above-described device configuration of M. Hartwell is shown in FIG.
It is shown in FIG. In the figure, reference numeral 141 denotes a substrate. 142
Denotes an H-shaped metal oxide thin film or the like formed by sputtering, and the electron emission portion 143 is formed by an energization process called forming described below.

Conventionally, in these surface-conduction electron-emitting devices, the electron-emitting portion 143 is generally formed by subjecting the conductive thin film 142 to an energization process called forming before performing electron emission. Was. That is, the energization forming means that a direct current voltage or a very slow rising voltage, for example, about 1 V / min is applied to both ends of the conductive thin film 142, and the conductive thin film is locally destroyed, deformed or altered. That is, the electron emitting portion 143 is formed in an electrically high resistance state. In the electron emitting portion 143, a crack may be generated in a part of the conductive thin film 142, and electrons may be emitted from the vicinity of the crack.

As a method of manufacturing an electron source substrate by arranging a large number of the surface conduction electron-emitting devices, photolithography has been conventionally used (Japanese Patent Laid-Open No. 6-12997). However, in this case, there are problems that a short circuit is likely to occur between the upper and lower wirings due to a defect near the interlayer insulating layer, a positioning margin in the manufacturing process is small, and a time man-hour is large.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an electron source substrate, a method of manufacturing the same, and an image display device which solve the above problems. is there.

[0011]

In order to achieve the above object, the present invention provides a first embodiment in which the layers are substantially orthogonal to each other with an interlayer insulating layer interposed therebetween.
And a second wiring are formed on the substrate surface of the matrix wiring board, and the first wiring and the second wiring are arranged in respective regions surrounded by the first wiring and the second wiring. In an electron source substrate having a pair of element electrodes respectively connected to wiring and a conductive thin film having an electron emission portion formed between the pair of element electrodes, the pair of element electrodes are substantially right triangle electrode portions. And a pair of connecting portions integrally formed with the electrode portion, the pair of electrode portions are arranged so as to face each other with a predetermined distance therebetween, and each connecting portion is provided with the first wiring or The present invention proposes an electron source substrate characterized in that an electron emitting portion is formed at substantially equal distances from the first wiring and the second wiring by connecting to the second wiring, respectively.

Further, the present invention is the above-mentioned method for manufacturing an electron source substrate, characterized in that the element electrode is first formed on the substrate, and then the first wiring is formed.

In the method for manufacturing an electron source substrate according to the present invention, first, an element electrode pair is formed on the substrate, and then a first wiring is formed so as to overlap the connection portion of one of the pair of element electrodes. Then, after manufacturing an interlayer insulating layer covering the upper surface of the first wiring, the second wiring is formed so as to overlap with the connection portion of the other electrode of the pair of element electrodes, and the manufacturing of the electron source substrate characterized by the above-mentioned. Is the way.

In the method for manufacturing an electron source substrate according to the present invention, first, an element electrode is formed on the substrate, and then a first wiring is formed so as to overlap with a connection portion of one of the pair of element electrodes. Then, an interlayer insulating layer having a connection cutout portion is formed above the connection portion so as to overlap the connection portion of the other electrode of the pair of element electrodes so as to be orthogonal to the first wiring, and then, is formed on the upper surface of the interlayer insulating layer. The method of manufacturing an electron source substrate is characterized by forming two wirings.

In the method for manufacturing an electron source substrate according to the present invention, first, an element electrode pair is formed on the substrate, and then a first wiring is formed so as to overlap the connecting portion of one of the pair of element electrodes. Then, after forming an interlayer insulating layer on the upper surface of the first wiring and covering the planned intersection portion of the first wiring and the second wiring, it is overlaid on the connection portion of the other electrode of the pair of element electrodes. And a second wiring is formed to form the electron source substrate.

The present invention is also the above-mentioned method for manufacturing an electron source substrate, in which the first wiring, the second wiring, the interlayer insulating layer, or the device electrode is formed by the thick film printing method.

The present invention is also the method for producing the above-mentioned electron source substrate, which is a surface conduction electron-emitting device in which the electron-emitting device is provided with an electron-emitting portion by subjecting a conductive thin film to an electric current treatment.

Further, the present invention is an electron source substrate manufactured by the above manufacturing method.

The present invention is also an image display device in which a pixel is formed by disposing a phosphor that emits visible light when irradiated with electrons, at a position facing each electron-emitting device on the electron source substrate.

According to the present invention having the above structure, in the simple matrix wiring substrate, two second wirings (first wirings) adjacent to the element electrodes connected to the first wirings (second wirings) are provided. It can be placed in the center of. By making the element electrode substantially trapezoidal, the first wiring and the second wiring are formed from each point in the minute gap formed by the pair of element electrodes.
The distances to the wirings are almost equal.

As a result, (A) In the above case, the connection point of the element electrode is located farthest from the adjacent wiring, so that the short circuit between the first wiring and the second wiring is significantly reduced. (B) In the above case, the length of the minute gap formed by the pair of element electrodes can be the longest in terms of design. (C) In the above case, since the distance from each wiring to each arbitrary point in the minute gap becomes equal, the potential distribution is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a configuration (plan view) of a typical electron-emitting device used for the electron source substrate of the present invention.

FIG. 2 shows a process flow chart of the manufacturing method. In the figure, 1 is an element electrode, 2 is a first wiring (signal side wiring or scanning side wiring), 3 is an interlayer insulating layer between the first wiring and the second wiring, and 4 is a second wiring ( Scanning side wiring or signal side wiring) 5 is a minute gap formed by the element electrodes. A film for forming an electron emitting portion is formed in this minute gap portion.

Hereinafter, according to the process flow chart of FIG.
The method of manufacturing the electron source substrate according to the present invention will be described in detail.

First, the device electrode 1 having a left-right non-equal length structure is formed on a previously washed substrate (FIG. 2A). The present electrode is provided for improving ohmic contact between the conductive thin film and each of the upper and lower wirings. Normally, the conductive thin film is a film that is significantly thinner than the conductor layer for wiring,
It is provided in order to avoid problems such as “wetting property” and “film thickness retention property”.

The device electrode 1 is composed of a substantially right-angled triangular electrode portion 15 and a substantially rectangular connecting portion 17 which are integrally formed, and has a substantially trapezoidal shape as a whole. A pair of device electrodes 1,
The reference numeral 1 forms a minute gap 5 by arranging the hypotenuses 19 of the substantially right-angled triangular electrode portion 15 so as to face each other and separated by a predetermined distance.

The features of the present invention will be described below.
The pattern of the element electrode is formed so that an arbitrary point in the minute gap 5 formed by the pair of element electrodes is equidistant from the connection portion of each wiring of the first wiring and the second wiring connected to the element electrode. To form.

With this structure, the degree of freedom is increased when the connecting portion between the device electrode 1 and the second wiring 4 is formed in the interlayer insulating layer 3 as shown in Example 1 described later. A preferable example of this is to form a connecting portion at the midpoint of two adjacent first wirings. In general, the wiring formed by the printing paste has a slightly widened wiring width due to sagging or the like during printing, but the above-described configuration significantly reduces short circuits between upper and lower wiring due to sagging or the like.

Further, the best example is the second step in the step immediately following the element electrode forming step, as shown in Example 2 described later.
Wiring is formed. By doing so, it is not necessary to form a connecting portion in the interlayer insulating layer. Therefore, problems due to sagging of the printing paste and the like are avoided.

As a method for forming the electrodes, a method using a vacuum system such as a vacuum vapor deposition method, a sputtering method, a plasma CVD method or the like is formed by printing and firing a thick film paste in which a solvent is mixed with a metal component and a glass component. There is a thick film printing method.

In order to maximize the effects of the present invention, a thick film printing method which does not require a photolithography process can be used to reduce the number of processes and time required most. However, it is desirable that the film thickness of the device electrode be small. Therefore, when the thick film printing method is used, it is preferable to use a so-called MOD paste composed of an organometallic compound as the paste used at that time. Of course, other film formation methods may be used, and the constituent materials are not particularly limited as long as they are electrically conductive materials.

Further, in the case of constituting the simplest process of the present invention, it is possible to simultaneously form the above-mentioned element electrode 1 and a portion with an electrode (not shown) for connection with an external circuit. It is possible. Also in this case, it is easy to use the thick film printing method, but it goes without saying that the film may be formed by the sputtering method or the like and the pattern may be formed by the photolithography method.

Next, the first wiring 2 is formed (see FIG. 2).
(B)). A method similar to the method of forming the element electrode 1 can be applied to the method of forming the wiring 2. However, in the case of the wiring 2, unlike the element electrode 1, a thicker film can reduce electric resistance. It is advantageous. Therefore, it is advantageous to use thick film printing. Of course, thin film wiring can be applied,
It takes time to increase the film thickness, and the extremely thick film is not realistic.

Next, the interlayer insulating layer 3 is formed (FIG. 2).
(C)). Here, as an example (the most complicated example) in FIGS. 1 and 2, a cutout portion 20 (concave pattern) for connection with the second wiring 4 is formed in the interlayer insulating layer.

The constituent material of the interlayer insulating layer may be any material as long as it can maintain the insulating property, and examples thereof include a SiO ₂ thin film and a film made of a thick film paste containing no metal component.

Next, the second wiring 4 is formed (see FIG. 2).
(D)). As a forming method, a method similar to that of the first wiring 2 can be applied.

Finally, a conductive thin film is formed to complete an element (one element) for the cold cathode electron beam source. As the film forming method and the electron emitting portion forming method, a conventional method can be applied as it is (described later).

Although only one element portion is shown in the figure, by forming a plurality of elements at the same time,
The configuration of the electron source substrate having the simple matrix configuration is completed.

It should be noted that the matrix structure may be a simpler structure. For example, if the scan side wiring is formed in the step subsequent to the step of forming the element electrodes as shown in the second embodiment, It is possible to connect the device electrodes to the wiring on the scanning side without forming a concave portion in the interlayer insulating layer as in the complicated example of No. 1.

Among the image display devices, the present invention provides excellent effects in a simple matrix type image display device using surface conduction electron-emitting devices, and particularly in a manufacturing method using a thick film printing method. Is.

Typical structure of surface conduction electron-emitting device,
For the manufacturing method and characteristics, see, for example, JP-A-2-568.
22.

The basic structure, manufacturing method and characteristics of the surface conduction electron-emitting device according to the present invention will be outlined below. FIG. 3A is a drawing (principle diagram) showing a schematic structure of an electron-emitting device according to the present invention. In the figure, 31 is a substrate, 35 and 36 are device electrodes, 34 is a conductive thin film, and 33 is an electron emitting portion. Further, 37 and 38 are wiring portions corresponding to the upper wiring and the lower wiring in FIG. 2, respectively.

Specific examples of the conductive thin film 34 include Pd,
Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Z
n, Sn, Ta, W, Pb and other metals, PdO, SnO
Oxides such as ₂ , In ₂ O ₃ , PbO and Sb ₂ O ₃ , Hf
Borides of B ₂ , LaB ₆ , CeB ₆ , YB ₄ , GdB _4, etc., TiC, ZrC, HfC, TaC, SiC, WC
Such as carbides, TiN, ZrN, HfN and other nitrides, S
It is a semiconductor such as i or Ge, or carbon.

As the method of forming the thin film, there are a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method and the like.

Various methods are conceivable for forming the surface conduction electron-emitting device, and one example thereof is shown in FIG.
A conductive thin film 34 is, for example, 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 a state in which the fine particles are dispersed and arranged but also a state in which the fine particles are adjacent to each other or overlap each other (islands). (Including a shape), and the particle size of the fine particles is several nm to several hundred nm, preferably 1 nm to 20 nm.

The electron emitting portion 33 is a high resistance crack formed in a part of the conductive thin film 34, and is formed by energization forming or the like. In addition, several nm to several tens of nanometers in the crack
It may have conductive fine particles having a particle diameter of m. The conductive fine particles contain at least a part of the elements forming the conductive thin film 34. Further, the electron emitting portion 33 and the conductive thin film 34 in the vicinity thereof may contain carbon and a carbon compound.

Hereinafter, referring to FIGS. 3, 4 and 5,
A method of forming the element will be described.

The following description describes a method of forming a single element, but it is also applicable to the method of manufacturing the novel electron source substrate according to the present invention described above.

1) After the insulating substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, the device electrodes 35 and 36 are formed on the surface of the insulating substrate 31 by the vacuum evaporation technique and the photolithography technique ( FIG. 4 (a1)). Any material may be used as the material of the device electrodes as long as it has electrical conductivity. For example, nickel metal may be used, and the device electrode interval L1 is 20 μm (preferably 10 to 30 μm), device. The electrode length W2 is 300 μm (100
~ 500 µm is preferred. ), And the film thickness d of the device electrodes 35 and 36 is 100 nm (preferably 50 to 300 nm). A thick film printing method may be used as a method of forming the device electrodes (electrodes in the vicinity of the electron emitting portion). In the case of the printing method, there is an organic metal paste (MOD) or the like.

Next, the conductor wiring portions 37 and 38 are formed (FIG. 4 (a2)).

2) Device electrode 35 provided on the substrate 31
And the substrate 3 on which the device electrodes 35 and 36 are formed between
By coating the organometallic solution on 1 and leaving it to stand,
An organometallic thin film is formed. The organic metal solution means Pd, Ru, Ag, Au, Ti, In, Cu, Cr,
It is a solution of an organometallic compound containing a metal such as Fe, Zn, Sn, Ta, W, or Pd as a main element. Then, the organometallic thin film is heated and baked, and patterned by lift-off, etching, etc. to form the conductive thin film 34 (FIG. 4).
(B)).

3) Subsequently, a voltage is applied between the device electrodes 35 and 36 by an energization process called forming to form an electron emitting portion 33 having a changed structure in the conductive thin film 34 (see FIG. 4 (c)). The electrically conductive thin film 34 is locally destroyed, deformed, or altered by this energization process, and a portion whose structure is changed is called an electron emission portion 33. The applicants have observed that the electron emitting portion 33 is composed of metal fine particles as described above.

FIG. 5 shows the voltage waveform during the forming process. A pulse waveform is particularly preferable as the voltage waveform, and when a voltage pulse having a constant pulse peak value is continuously applied (see FIG. 5).
(A)) and the case of applying a voltage pulse while increasing the pulse peak value (FIG. 5 (b)). First, a case where the pulse peak value is a constant voltage (FIG. 5A) will be described.

In FIG. 5A, 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 is set. (Peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes under an appropriate vacuum atmosphere, for example, in a vacuum atmosphere of about 10 ⁻⁵ torr. .

T1 and T2 in FIG. 5B are shown in FIG.
As in (a), the peak value of the triangular wave (peak voltage during energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere. In the energization forming process in this case, the element current is measured at a voltage that does not locally break or deform the conductive thin film 2 during the pulse interval T2, for example, a voltage of about 0.1 V, and the resistance value is obtained, For example, the energization forming is terminated when the resistance is 1 MΩ or more.

Next, it is desirable to perform a process called an activation process on the element for which energization forming has been completed. The activation step is, for example, a vacuum degree of about 10 ⁻⁴ to 10 ⁻⁵ torr,
Similar to the energization forming, it is a process of repeatedly applying a voltage pulse with a constant pulse peak value. Carbon or a carbon compound derived from an organic substance existing in a vacuum is deposited on a conductive thin film, and the device electrode If, discharge This is a process of significantly changing the current Ie. The activation process is the device current If
While measuring the emission current Ie, the process ends when the emission current Ie is saturated, for example. Further, it is preferable that the applied voltage pulse is an operation drive voltage.

As described above, when forming the electron emitting portion described above, the forming process is performed by applying the 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. Alternatively, a desired waveform such as a rectangular wave may be used, and the crest value, pulse width, pulse interval, etc. are not limited to the above values, and a desired value may be selected if the electron-emitting portion is well formed. can do.

Here, carbon or carbon compound means graphite (both single and polycrystalline) and amorphous carbon (a mixture of amorphous carbon and polycrystalline graphite), and its film thickness is 50 nm or less is preferable,
More preferably, it is 30 nm or less.

It is preferable to drive the electron-emitting device thus produced in an atmosphere having a vacuum degree higher than the vacuum degree in the forming step and the activation step. In addition, it is desirable to operate and drive after heating at 80 ° C. to 150 ° C. in an atmosphere of a higher degree of vacuum. The degree of vacuum higher than the degree of vacuum formed by the forming process and activation is, for example, a degree of vacuum of about 10 ⁻⁶ or more, more preferably an ultrahigh vacuum system, and a new carbon or carbon compound is used as the conductive thin film. The degree of vacuum is such that it hardly deposits on top. By doing so, the device current If and the emission current Ie can be stabilized.

Basic characteristics of the electron-emitting device according to the present invention produced by the above device structure and manufacturing method will be described with reference to FIGS. 6 and 7.

FIG. 6 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring the electron emission characteristics of the element having the configuration shown in FIG. In FIG. 6, 31 is an insulating substrate, and 35, 3
Reference numeral 6 is a device electrode, 34 is a conductive thin film, and 33 is an electron emitting portion. Further, 61 is a power source for applying a device voltage Vf to the device, and 60 is a conductive thin film 34 between the device electrodes 35 and 36.
Ammeter for measuring the device current If flowing through the device, 64 is an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device, 63 is a high-voltage power supply for applying a voltage to the anode electrode 64, 62 is an electron emitting portion 3 of the device
3 is an ammeter for measuring the emission current Ie emitted from the device 3. The device current If and the emission current I of the electron-emitting device
When measuring e, the power source 61 is applied to the device electrodes 35 and 36.
And an ammeter 60 are connected to each other, and an anode electrode 64 to which a power source 63 and an ammeter 62 are connected is arranged above the electron-emitting device. Further, the present electron-emitting device and the anode electrode 64
Is installed in a vacuum device 65, and the vacuum device is equipped with equipment necessary for a vacuum device such as an exhaust pump and a vacuum gauge, which are not shown, so that measurement and evaluation of this element can be performed under a desired vacuum. It has become. The voltage of the anode electrode is 1
It is preferable to measure in the range of 10 to 10 kV and the distance H between the anode electrode and the electron-emitting device in the range of 3 to 8 mm.

FIG. 7 shows a typical example of the relationship between the emission current Ie and the device current If and the device voltage Vf measured by the measurement / evaluation apparatus shown in FIG. Note that FIG. 7 is shown in arbitrary units, and the emission current Ie is about 10 times the device current If.
It is about 1/00. As is apparent from the figure, the electron-emitting device has three characteristics with respect to the emission current Ie.

First, in the present device, when a device voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 7) is applied, the emission current Ie rapidly increases, while below the threshold voltage, the emission current Ie. Is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie depends on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.

Thirdly, the amount of charge captured by the anode electrode 64 can be controlled by the time for which the device voltage Vf is applied.

Since the electron-emitting device according to the present invention has the above characteristics, it is expected to be applied to various fields. Further, FIG. 7 shows an example of the characteristic (MI) in which the element current If monotonously increases with respect to the element voltage Vf. However, in addition to this, the element current If is a voltage-controlled negative resistance with respect to the element voltage Vf. In some cases, the (VCNR) characteristic is exhibited (not shown).
Also in this case, the electron-emitting device has the above-mentioned three characteristics. The surface conduction electron-emitting device in which the conductive fine particles are dispersed in advance can be configured by partially modifying the basic manufacturing method of the basic device structure of the present invention.

As a typical structure of a color image display device to which the present invention is applied, first, a plurality of electron-emitting devices manufactured by the manufacturing method according to the present invention are formed on a substrate 31 (FIG. 8). After the substrate 31 is fixed on the rear plate 32, the face plate 40 (which is formed by forming the phosphor film 38 and the metal back 39 on the inner surface of the glass substrate 37) is supported 5 mm above the substrate 31 by the supporting frame 4.
3, the face plate 40, the support frame 4
3. Frit glass is applied to the joint of the rear plate 32, and the temperature is 400 ° C to 5 in the air or nitrogen atmosphere.
It can be sealed by baking at 00 ° C. for 10 minutes or more (FIG. 8). Further, the substrate 31 can be fixed to the rear plate 32 by frit glass. In FIG. 8, 34 is an electron emitting portion, 35 and 36 are the first and second wirings 2, respectively.
4 is an element electrode connected to. Although the face plate 40, the support frame 43, and the rear plate 32 constitute the envelope 41 here, the rear plate 32 is mainly the substrate 3
Since it is provided for the purpose of reinforcing the strength of No. 1, if the substrate 31 itself has sufficient strength, the rear plate 3 which is a separate body is provided.
2, the support frame 43 is directly sealed to the substrate 31, and the face plate 40, the support frame 43, and the substrate 31 constitute the envelope 41. A metal back 39 is usually provided on the inner surface side of the phosphor film 38.

The purpose of the metal back is to serve as an electrode for applying an electron beam accelerating voltage by improving the brightness by specularly reflecting, to the face plate 40 side, the light to the inner surface side of the light emitted from the phosphor. This is to protect the phosphor from damage caused by collision of negative ions generated in the envelope.

The metal back is formed by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after forming the phosphor film, and then vacuum depositing Al. The face plate 40 may be provided with a transparent electrode (not shown) on the outer surface side of the phosphor film 38 in order to further increase the electric conductivity of the phosphor film 38. When performing the above-mentioned sealing, in the case of a color image display device, it is necessary to sufficiently align the phosphors corresponding to the respective colors with the electron-emitting devices. The atmosphere in the glass container thus created is exhausted by a vacuum pump through an exhaust pipe (not shown),
After reaching a sufficient degree of vacuum, a voltage is applied between the device electrodes 35 and 36 through the terminals Dx1 to Dxm and Dy1 to Dyn (not shown) outside the container, and the above-described forming is performed to form the electron emitting portion 34. Then, an electron-emitting device is created. Finally,
At a vacuum degree of about 10 ⁻⁶ torr, the exhaust pipe is heated and welded to seal the envelope to complete the image display device. Furthermore, in order to maintain the degree of vacuum after sealing, a step of getter processing is performed. This is a process of forming a getter vapor deposition film by heating a getter arranged at a predetermined position (not shown) of the image display device by resistance heating or high frequency heating immediately before or after the sealing. Is. As a getter, Ba or the like is usually the main component, and the degree of vacuum is maintained by the adsorption action of the vapor deposition film.

In the image display device constructed by the above manufacturing method, each electron-emitting device has a terminal D outside the container.
Electrons are emitted by applying a voltage through x1 to Dxm or Dy1 to Dyn, and a high voltage of several kV or more is applied to the metal back 39 or the transparent electrode through the high voltage terminal Hv to accelerate the electron beam and collide with the phosphor film 38. An image is formed by causing the phosphor to excite and emit light. Of course, these configurations are the outlines of the configurations necessary for producing the image display device, and the materials and the like of each member are not limited to the above contents.

The phosphor film 38 is composed of only phosphors in the case of monochrome display, but in the case of color display, it is composed of a black member 92 called a black stripe or a black matrix and a phosphor 93 depending on the arrangement of the phosphors. (Fig. 9). The purpose of providing the black member is to make the mixed colors of the three primary color phosphors, which are necessary in the case of color display, different from each other by making the portions of the phosphors 93 differently colored, and to reflect external light on the phosphor film 38. This is to suppress the decrease in contrast due to. As the black material,
Usually, graphite is the main component in many cases, but the material is not limited to this as long as it is a material having electrical conductivity and little transmission and reflection of light.

As a method of applying the phosphor to the glass substrate 37, in the case of monochrome, there are a precipitation method, a printing method and the like. For color, there is a slurry method or the like. Of course, it is also possible to use a printing method in color.

[0075]

EXAMPLES Next, examples will be used to specifically describe an image display device using an electron source substrate, particularly a surface conduction electron-emitting device, and manufacturing methods thereof.

[Embodiment 1] A first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view, and FIG. 2 is a process diagram illustrating a manufacturing process. The present embodiment is an example in which a cutout portion 20 (recess portion) is formed in a connection portion between an element electrode and a second wiring (scanning side wiring) in an interlayer insulating layer, and a manufacturing method of the most complicated structure in the present invention. Is.

First, a cleaned glass substrate (here,
The element electrode 1 was formed on a soda-lime glass substrate). In this example, a screen printing method was used as a film forming method. The thick film paste material used here is MOD paste, and the metal component is Au. The printing method is a screen printing method. After printing, 1 at 70 ℃
It was dried for 0 minutes, and then main firing was performed. Firing temperature is 580
At ° C, the peak retention time is about 8 minutes. The film thickness after printing and firing was ˜0.3 μm.

As shown in FIG. 2, the pattern was a substantially trapezoidal pattern having non-equal right and left lengths. At the same time, a lead electrode (not shown) for connection with an external drive circuit was formed. This shortens the process by one process. Of course, it does not matter if they are formed separately.

Next, a first wiring (signal side wiring) was formed. A screen printing method was used as a film forming method, and Ag-containing thick film paste NP-4028A manufactured by Noritake Company was used as a paste material. The film thickness after printing and firing was ˜13 μm.

Next, the interlayer insulating layer 3 was formed. In this embodiment, a thick film screen printing method was used similarly to the wiring. The paste material is a paste containing PbO as a main component and a glass binder mixed. The firing temperature is 580 ° C. and the peak holding time is about 8 minutes. Film thickness after printing and firing is ~ 30
μm. Normally, printing and baking are performed twice on the insulating layer in order to ensure insulation between the upper and lower first wirings and the second wirings. The film formed by the thick film paste is usually a porous film. Therefore, after printing and firing once, printing is performed again and the second film is printed and fired so as to embed the porous state of the first film. This ensures insulation. This example also follows this. Here, the effect that the minute gap 5 formed by the element electrode and the second wiring is 45 degrees, which is a feature of the present invention, is exhibited. That is, according to the configuration of the present invention, the position where the connection portion (recess portion) between the element electrode and the second wiring (scanning side wiring) layer is formed is between the first wiring (signal side wiring) layer. If it is possible, it can be formed at any position. Here, by forming the connection portion just at the midpoint portion of the first wiring, it becomes possible to remarkably reduce the short circuit between the upper and lower wirings.

Finally, a second wiring (scanning side wiring) layer is formed. As in the case of the first wiring, a thick film screen printing method was used as the forming method, and NP-4035C of Noritake Company was used as the paste material. Firing temperature is 45
At 0 ° C., peak retention time is about 8 minutes. The film thickness after printing and firing was ˜15 μm.

Thus, the matrix wiring portion is completed. Of course, the paste material, printing method, etc. are not limited to those described here.

After the wiring is completed, an electron emitting portion is formed. First, the organic palladium (CCP4230, CCP4230,
Okuno Chemical Industries Co., Ltd. spin coating is applied by a spinner, followed by heat treatment at 300 ° C. for 10 minutes to form a conductive thin film 5 made of PdO. The conductive thin film thus formed is composed of fine particles containing Pd as a main element, and has a film thickness of 10 nm and a sheet resistance value of 5 × 10 ⁴ Ω.
/ □. The fine particle film described here is a film in which a plurality of fine particles are gathered. The fine structure thereof is not only a state in which the fine particles are individually dispersed and arranged, but also a state in which the fine particles are adjacent to each other or overlapped (the island shape is also used). ), And the particle size refers to the diameter of the fine particles whose particle shape can be recognized in the above state.

By patterning this palladium film by using the photolithography method, the manufacturing process of the element before forming is completed.

As a forming method, a conventional method can be adopted. In this example, the following conditions were set (see FIG. 5). In FIG. 5, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1 millisecond, T1
2 is set to 10 milliseconds, the peak value of the triangular wave (peak voltage at the time of forming) is set to 14 V, and the forming process is about 1 ×
It was carried out for 60 seconds under a vacuum atmosphere of 10 ^@ 6 torr.

[0086] Next, after the forming of all surface conduction electron-emitting device is finished, 1 × exhaust tube 10 ^{over 6} torr vacuum of about (not shown) of enclosure outside welded by heating with a gas burner sealing I stopped.

Finally, a getter process was performed in order to maintain the degree of vacuum after sealing. This is a process for forming a vapor deposition film by heating a getter arranged at a predetermined position (not shown) in the image display device by a heating method such as high frequency heating immediately before sealing. The getter is mainly composed of Ba or the like.

In the image display device of the present invention completed as described above, each electron-emitting device has a terminal Dx outside the container.
A scanning signal and a modulation signal are applied by signal generation means (not shown) through 1 to Dxm and Dy1 to Dyn, respectively, thereby causing electrons to be emitted and the high voltage terminal Hv
, A high voltage of several kV was applied to the metal back film, and an electron beam was accelerated to collide with, excite, and emit light on the fluorescent film, thereby displaying an image.

[Second Embodiment] A second embodiment will be described with reference to FIGS. FIG. 10 is a plan view, and FIG.
Is a process drawing. The structure of the electron source substrate of the present embodiment is the simplest structure of the present invention.

First, the device electrode 81 is formed on a cleaned glass substrate (here, a soda lime glass substrate is used) in the same manner as in Example 1 (FIG. 11A). Also in this example, as in Example 1, a thick film printing method was used as a film forming method. The thick film paste material used here was MOD paste, and Pt was used as the metal component in this example. The printing method is a screen printing method. After printing, it was dried at 70 ° C. for 10 minutes and then subjected to main firing. The firing temperature is 580 ° C and the peak holding time is about 8
Minutes. The film thickness after printing and firing was ˜0.25 μm.

The pattern formed a left-right asymmetrical trapezoidal pattern. At the same time, a lead-out electrode (not shown) for connection with an external drive circuit is also formed. This shortens the process by one process.

Next, in this embodiment, the wiring layer 84 on the scanning side is formed.
Are formed (FIG. 11B).

Here, the effect that the minute gap 85 formed by the element electrodes and the wiring layer 84 on the scanning side are 45 degrees is a feature of the present invention. That is, according to the configuration of the present invention, the connection portion between the device electrode and the scanning-side wiring layer 84 is large, and it is not necessary to provide, for example, a concave portion for connection in the interlayer insulating layer 83 formed in the next step. .
This means that when the interlayer insulating layer is formed by printing, a good film can be formed without pattern collapse or the like. Further, since there is no recessed portion, there is no short circuit between the upper and lower sides due to the sagging of the paste when the signal side wiring layer is formed.

Next, the interlayer insulating film 83 is formed. In this example, the thick film printing method was used. The paste material is a paste containing PbO as a main component, a glass binder and a resin. The firing temperature was 580 ° C. and the peak holding time was about 8 minutes. The film thickness after printing and firing was ˜30 μm. The forming method was printing twice and firing twice as in Example 1 (FIG. 11C).

Finally, the signal side wiring layer 82 was formed (FIG. 11D). As in the case of the scanning side wiring layer, the thick film screen printing method was used as the forming method, and NP-4035C of Noritake Company was used as the paste material. The firing temperature is 450 ° C. and the peak holding time is about 8 minutes. printing,
The film thickness after firing was ˜15 μm.

Thus, the matrix wiring portion is completed. Of course, the paste material, printing method, etc. are not limited to those described here.

The subsequent steps were made in the same manner as in Example 1.

[Embodiment 3] A third embodiment is shown in FIGS. 11 is a plan view and FIG. 13 is a process drawing. The present embodiment is an example in which the second embodiment is further simplified, and the interlayer insulating layer 93 is connected to upper and lower wirings (first and second wirings 92 and 9).
It is formed only near the intersection of 4). Since other configurations are similar to those of the first embodiment, the description thereof will be omitted.

Reference numeral 91 is a device electrode.

With such a structure, the influence on the trajectory of the electron beam emitted from the electron emitting portion is alleviated.

In this embodiment, since the interlayer insulating layer is only at the intersection of the upper and lower wirings, it is possible to reverse the formation order of the scanning side wiring and the signal side wiring.

[0102]

As described above, according to the present invention, since the electron source substrate is constructed as described above, when the cutout portion for connecting the scanning side wiring and the device electrode is formed in the interlayer insulating layer, Can be formed at the midpoint of the adjacent signal side wiring. By making the element electrodes into a substantially trapezoidal shape, any point in the minute gap formed by a pair of element electrodes is located equidistant from each of the scanning-side and signal-side wirings cut by the element electrodes. Can be formed. As a result, (A) in the above case, the connection portion is located at the farthest position from each adjacent signal-side wiring, so that the short-circuit probability between the upper and lower wirings is significantly reduced. (B) In the above case, the element electrode is formed. The length of the minute gap to be formed has the effect that it can be made the longest in terms of design. In particular, when an electron source substrate is manufactured using a thick film screen printing method, the method has high reliability and an easy manufacturing process. Can be manufactured in.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a basic configuration of an element portion of an electron source substrate of the present invention.

2A to 2D are process drawings showing an example of a method for manufacturing an electron source substrate of the present invention.

FIG. 3A is a plan view and FIG. 3B is a side view showing a typical configuration of a surface conduction electron-emitting device used in the present invention.

4 (a1) to 4 (c) are explanatory views showing process steps of a method of manufacturing a surface conduction electron-emitting device.

5A and 5B are graphs showing forming voltage waveforms.

FIG. 6 is a schematic diagram showing a configuration of an electron emission characteristic measurement / evaluation apparatus for an electron emission element.

FIG. 7 is a graph showing typical discharge characteristics of a surface conduction electron-emitting device.

FIG. 8 is a perspective view illustrating a configuration example of an image display device of the present invention.

9A and 9B are plan views showing a structure of a phosphor.

FIG. 10 is a plan view showing the element structure of Example 2;

11A to 11D are explanatory views showing the manufacturing process of the second embodiment.

FIG. 12 is a plan view showing the configuration of an element of Example 3.

13 (a) to 13 (d) are explanatory views showing a manufacturing process of a third embodiment.

FIG. 14 is a plan view showing a configuration of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

 1 Element Electrode 2 First Wiring 3 Interlayer Insulation Layer 4 Second Wiring 5 Small Gap 6 Notch

Claims (9)

[Claims] 1. A matrix wiring board having a first wiring and a second wiring formed on a substrate surface and being substantially orthogonal to each other with an interlayer insulating layer interposed between the matrix wiring board and the first wiring and the second wiring. A pair of element electrodes respectively arranged in each region and connected to the first wiring and the second wiring, and a conductive thin film having an electron emitting portion formed between the pair of element electrodes. In the electron source substrate, the pair of element electrodes is composed of a substantially right-angled triangle electrode portion and a connection portion integrally formed with the electrode portion, and the pair of electrode portions are spaced apart from each other by a predetermined distance along the hypotenuse portion of the triangle. The electron emitting portions are formed at substantially equal distances from the first wiring and the second wiring by disposing them facing each other and connecting the respective connecting portions to the first wiring or the second wiring, respectively. An electron source substrate characterized by the above. 2. The method of manufacturing an electron source substrate according to claim 1, wherein the device electrode is first formed on the substrate, and then the first electrode is formed.
A method of manufacturing an electron source substrate, comprising: 3. The method of manufacturing an electron source substrate according to claim 1, wherein an element electrode pair is first formed on the substrate, and then the first wiring is overlapped with a connection portion of one electrode of the pair of element electrodes. An electron source substrate, which is formed, and then covers the upper surface of the first wiring to form an interlayer insulating layer, and then forms the second wiring so as to overlap the connection portion of the other electrode of the pair of element electrodes. Manufacturing method. 4. The method of manufacturing an electron source substrate according to claim 1, wherein an element electrode is first formed on the substrate, and then a first wiring is formed so as to overlap with a connection portion of one electrode of the pair of element electrodes. Then, an interlayer insulating layer is formed so as to overlap the connecting portion of the other electrode of the pair of device electrodes and has a connecting cutout portion above the connecting portion so as to be orthogonal to the first wiring, and then, the upper surface of the interlayer insulating layer is formed. A method of manufacturing an electron source substrate, comprising forming a second wiring on the substrate. 5. The method of manufacturing an electron source substrate according to claim 1, wherein an element electrode pair is first formed on the substrate, and then the first wiring is overlapped on a connection portion of one electrode of the pair of element electrodes. Then, after forming an interlayer insulating layer on the upper surface of the first wiring and covering the planned intersection portion of the first wiring and the second wiring, the connection portion of the other electrode of the pair of element electrodes A method of manufacturing an electron source substrate, comprising: forming a second wiring on the substrate. 6. A first wiring, a second wiring, an interlayer insulating layer,
Alternatively, the method of manufacturing an electron source substrate according to claim 2, wherein the element electrode is formed by a thick film printing method. 7. The electron source substrate according to claim 2, wherein the electron-emitting device is a surface-conduction electron-emitting device in which an electron-emitting portion is formed by subjecting a conductive thin film to an electrification treatment. Production method. 8. An electron source substrate manufactured by the manufacturing method according to claim 2. 9. An image display in which a pixel is formed by disposing a phosphor that emits visible light when irradiated with electrons at a position facing each electron-emitting device of the electron source substrate according to claim 1 or 8. apparatus.