JP3472033B2 - Method of manufacturing electron source substrate and method of manufacturing image forming apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface conduction electron-emitting device, an electron source using the electron-emitting device, an image forming apparatus using the electron source, and manufacturing methods thereof.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, which are roughly classified into a hot cathode electron-emitting device and a cold cathode electron-emitting device. Among them, the cold cathode electron-emitting device is a surface conduction electron-emitting device, a field-emission electron-emitting device (hereinafter referred to as “FE type”), a metal / insulating layer / metal-type electron-emitting device (hereinafter referred to as “MIM type”). , Etc.) are known. As an example of the surface conduction electron-emitting device type, M.
I. Elinson, Radio Eng. Elect
ron Phys. , 10, 1290 (1965) and the like and other examples described later. In the surface conduction electron-emitting device, electrons are emitted by passing a current through a thin film of a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using the SnO ₂ thin film by Erinson et al., One using the Au thin film [G. Dittmer: Thin Solid Fil
ms, 9, 317 (1972)], In ₂ O ₃ / SnO
₂ Thin film [M. Hartwell and C.I.
G. Fonstad: IEEE Trans. EDC
onf. , 519 (1975)], a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, page 22 (1983)] and the like. As a typical example of these surface conduction electron-emitting devices, the above-mentioned M. The Hartwell device configuration is schematically shown in FIG. In the figure, 001 is a substrate. A conductive thin film 004 is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and the electron emission portion 005 is formed by an energization process called energization forming described later. The element electrode spacing L1 in the figure is set to 0.5 to 1 mm, and W'is set to 0.1 mm. Conventionally, in these surface conduction electron-emitting devices, before the electron emission, the conductive thin film 004 is preliminarily subjected to an energization process called energization forming.
It was common to form 05. That is, the energization forming is an electron in which a direct current voltage or a very slow rising voltage is applied to both ends of the conductive thin film 004 to locally destroy, deform or alter the conductive thin film to make it an electrically high resistance state. That is, the emission part 005 is formed. In the electron emitting portion 005, a crack is generated in a part of the conductive thin film 004, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming process is one in which a voltage is applied to the conductive thin film 004 and a current is passed through the device so that electrons are emitted from the electron-emitting portion 005. Since this surface conduction electron-emitting device has a simple structure and is easy to manufacture, it has an advantage that many devices can be arrayed over a large area. Therefore, application research of a charged beam source, a display device, etc., which makes use of this characteristic has been made (for example, Japanese Patent Laid-Open No. 64-31332 and Japanese Laid-Open Patent Publication No.
283749, JP-A-2-257552, etc.). Further, in image forming apparatuses such as display devices, in particular, flat-panel display devices using liquid crystal have become widespread in place of CRTs in recent years, but since they are not self-luminous, they must have a backlight. Therefore, development of a self-luminous display device has been desired. An example of the self-luminous image forming apparatus is an image forming apparatus that is a display device in which a plurality of surface conduction electron-emitting devices are arranged and a phosphor that emits visible light by electrons emitted from the electron source is combined. (Eg, USP 50668883).

[0003]

In manufacturing an image forming apparatus using the surface conduction electron-emitting device, each surface conduction electron-emitting device and a device for driving the device are connected to a device electrode. Screen printing may be used in order to realize the necessary wiring on the substrate over a large area at low cost. Also, as the substrate, a glass plate which is easily available as a large substrate at a low cost is adopted as the substrate. However, the wiring formed by screen printing on the glass substrate has its outer periphery receded by about 5 to 10 μm when the printing paste is dried and fired, so that the wiring width is reduced to about 10 to 20 μm. ,
Further, fine particles of the wiring may remain in the region where the wiring has receded.

Since this residue has weak adhesion to the substrate, it moves inside when the image forming apparatus is assembled, and if it exists near the surface conduction electron-emitting device, it may adversely affect the characteristics of this device. There is. In addition, since the width of the wiring changes, a margin must be taken in advance when designing the wiring so as not to connect to the element electrodes, which is a surface conduction type for high resolution of the image forming apparatus. In some cases, the high-density arrangement of electron-emitting devices was hindered. Furthermore, since the wiring is formed using screen printing, it is not possible to obtain the same accuracy as in photolithography, and it is necessary to align the surface conduction electron-emitting device with the phosphor of the face plate when assembling the image forming apparatus. There were difficulties. Also,
The element electrode of the surface conduction electron-emitting device is provided for electrical connection between the conductive thin film and the wiring, which will be described later, but if the thickness of the element electrode is too thick compared to the thickness of the conductive thin film, the element electrode is electrically conductive at the end. There is a case where a step breakage of the thin film may occur, and for that purpose, it is better that the thickness of the device electrode is thin.

According to the present invention, when wiring is formed by screen printing or the like, the wiring can be formed with high accuracy without adversely affecting the surface conduction electron-emitting device, and the density of display pixels can be increased. It is an object of the present invention to provide a method for manufacturing an image forming apparatus.

[0006]

According to the present invention, a plurality of electron-emitting devices each having a conductive thin film having an electron-emitting portion and a pair of device electrodes are arranged in a matrix, and the device is provided for driving the electron-emitting devices. In a method of manufacturing an electron source substrate in which a plurality of lower wirings connected to electrodes and a plurality of upper wirings are formed to intersect with each other with an insulating layer in between , a thin film is entirely formed on the substrate.
After the formation, the plurality of lower wirings are formed on the thin film.
And a step of patterning the thin film to form the pair of devices.
The element electrode that constitutes one of the electrodes and the lower wiring
Exists as a base and faces one of the device electrodes
In such a way that a part of the lower wiring protrudes from the lower wiring,
The other constituting one of the device electrodes, a manufacturing method of including electron source substrate and the step, the forming the element electrodes co <br/> with the direction of the lower wiring.

[0007] method of manufacturing an electron source substrate of the above SL is suitable for use in the method of manufacturing an image forming apparatus.

As described above, in the present invention, the lower wiring formed first is formed on the common element electrode.
Since both the wiring and the element electrode are made of a metal material or a metal as a main component, the wiring material and the element electrode material have good adhesion even after the heating step. Even after passing through, it is possible to form a pattern with high accuracy and less shrinkage of the wiring width. At the same time, it is unlikely that the edge of the wiring film recedes and the residue remains. Even if a slight receding occurs and the residue remains, the adhesiveness is good and the residue moves to adversely affect the element. There is nothing to give.

The present invention is particularly effective when the wiring is formed by printing, particularly by using a thick film printing method such as screen printing and coating and baking. Since the wiring on the common element electrode has little width shrinkage during firing, it is possible to form a pattern having a line width almost as designed. At the same time, it is unlikely that the edge of the wiring film recedes and the residue remains. Even if a slight receding occurs and the residue remains, the adhesiveness is good and the residue moves to adversely affect the element. There is nothing to give.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1A is a completed view of an electrode portion and a wiring portion of the present invention, and FIG. 1B shows a device electrode and a lower wiring (a lower wiring formed first at an intersection is called a lower wiring,
The upper wiring formed thereafter is referred to as upper wiring. same as below. ) Is the figure which showed only. Here, 1 is a substrate, 5 and 6
Is an element electrode formed by processing a conductive thin film. In this figure, 5 is a common element electrode, and the element electrodes 6 are island-shaped and independent. The wiring 3 is formed on the common element electrode 5. Reference numeral 7 is an insulating layer formed so as to be orthogonal to the wiring 3, and 8 is a wiring formed on the insulating layer 7 so as to have a projecting portion connected to the device electrode 6.

In the present invention, the common element electrode may be present as a base of the wiring formed first. For example, the wiring can be formed by screen printing after forming a common element electrode (preferably also the other island-shaped element electrode at the same time) by offset printing or photolithography. It is also possible to form the lower electrode at a predetermined position after forming the device electrode material on the entire surface or a necessary portion and then pattern the device electrode by an appropriate method such as photolithography. However, screen printing is not as good as photolithography in terms of positional accuracy, so the position of the device electrode that was previously built
It is difficult to align the wiring with accuracy as high as photolithography. Therefore, when the positional accuracy is strictly required, the latter forming method can form the device electrodes 5 and 6 by photolithography in consideration of the position of the wiring 3 formed earlier. It is possible to improve the relative positional accuracy of the element electrodes. Furthermore, by delaying the patterning time of the device electrode by photolithography than the formation of the wiring, it is possible to further improve the accuracy. Next, this manufacturing method will be described with reference to FIG. 2 which is a sectional view. First, the conductive thin film 2 is uniformly formed on the well-washed insulating substrate 1 (FIG. 2A). The conductive thin film 2 may be formed by any method, for example, vacuum film formation, printing or coating. A stripe-shaped wiring 3 pattern having a width of several 10 μm to several 100 μm is formed on the substrate 1 by screen printing on the conductive thin film 2 (FIG. 2B). This wiring 3
The printing paste forming the pattern is dried and fired. The solvent component of the printing paste evaporates by the drying process,
The binder component of the printing paste is decomposed by firing and removed from the inside of the wiring. The remaining metal fine particles bond at the portions in contact with each other to form an irregular and three-dimensional network structure made of metal. The space portion of the mesh structure is filled with glass fine particles contained in the paste that are melted and hardened to reinforce the metal mesh structure and strengthen the adhesion with the substrate 1. At this time, the wiring 3 tends to shrink, but if the conductive thin film 2 layer is previously drawn down as in the present invention, the metal component in the wiring 3 will be the conductive thin film 2.
And the wiring 3 is fixed in place, the contraction force of the wiring 3 can be counteracted and the contraction of the wiring 3 can be prevented. Next, a photoresist 4 layer is formed on the substrate in which the wiring 3 is formed in order to process the conductive thin film 2 into the desired device electrodes 5 and 6 (FIG. 2C). Here, in FIG. 2, the photoresist 4 layer is formed only in a portion other than the wiring 3, but the present invention is not limited to this structure. The photoresist 4 is exposed and developed to be processed into desired device electrodes 5 and 6 (FIG. 2D). The exposed portion of the conductive thin film 2 is removed, and the conductive thin film 2 is processed into the shapes of the device electrodes 5 and 6. The conductive thin film 2 may be removed by any method, for example, wet etching, dry etching or sandblasting.
The photoresist 4 is peeled off (see FIG. 2F and FIG.
(B)), a striped insulating layer 7 is formed so as to be orthogonal to the wiring 3 as shown in FIG. 1A, and a portion of the wiring 8 excluding the protruding portion is formed so as to overlap the insulating layer 7. A wiring-formed substrate is completed (FIG. 1A). Wiring materials are Au, A
g, Cu, Pd, etc. and metal fillers such as a mixture thereof,
Melts at about 400 to 600 ° C., for example Pb, B, B
A product obtained by firing a printing paste containing glass fine particles whose main component is an oxide such as i or Si is used.

The structure of the entire image forming apparatus of the present invention will be described below with reference to the drawings. First, the basic structure of the surface conduction electron-emitting device used in the present invention is roughly classified into
There are two types: a planar surface conduction electron-emitting device and a vertical surface conduction electron-emitting device. The configuration of the planar surface conduction electron-emitting device is as shown in FIG. 6 (schematic diagram).
6A is a plan view and FIG. 6B is a sectional view. In FIG. 6, 001 is a substrate, 002 and 003 are element electrodes, and 004.
Is a conductive thin film, and 005 is an electron emitting portion. As the substrate 001, quartz glass, glass having a reduced content of impurities such as Na, soda lime glass, a glass substrate on which SiO ₂ is deposited by a sputtering method, a ceramic substrate such as alumina, or the like can be used. Opposing element electrodes 002,
As a material of 003, a general conductive material can be used, and Ni, Cr, Au, Mo, W, Pt, Ti, A can be used.
Metals or alloys such as 1, Cu, Pd and Pd, As, A
g, Au, printed conductors composed of RuO _2, metal or metal oxide such as Pd-Ag and glass, etc., In ₂ O ₃ -S
It can be selected from transparent conductors such as nO ₂ and semiconductor conductor materials such as polysilicon. Element electrode spacing L1,
The element electrode length W2, the shape of the conductive thin film 004, and the like are designed in consideration of the applied form and the like. Element electrode spacing L1
Is preferably in the range of several thousand angstroms to several hundreds of μm, and more preferably in the range of 1 μm to 100 μm in consideration of the voltage applied between the device electrodes. The device electrode length W2 is in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics. Element electrode 00
The film thickness d of 2,003 is 100 angstroms to 1
It is in the range of μm. In addition to the structure shown in FIG. 6, a conductive thin film 004 and opposing device electrodes 002 and 003 may be stacked in this order on the substrate 001.

In order to obtain good electron emission characteristics, it is preferable to use a fine particle film made of fine particles as the conductive thin film 004. The film thickness is appropriately set in consideration of the step coverage to the device electrodes 302 and 303, the resistance value between the device electrodes 002 and 003, the forming conditions described later, etc., but is usually in the range of several angstroms to several thousand angstroms. Is more preferable, and more preferably in the range of 10 angstroms to 500 angstroms. The resistance value is such that Rs is 10 ² to 10 ⁷ Ω
Is the value of. Rs has a thickness t, a width w, and a length l.
The resistance R of the thin film is a value that appears when R = Rs (l / w), and Rs = ρ /, where ρ is the resistivity of the thin film material.
It is represented by t. In the specification of the present application, the forming process will be described by taking an energization process as an example, but the forming process is not limited to this, and any method can be used as long as it is a method of forming a crack in a film to form a high resistance state. Good.

The material forming the conductive thin film 004 is Pd,
Pt, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, Zn, Sn, Ta, W, Pd and other metals, PdO, S
nO ₂ , In₂ O₃ , PbO, Sb₂ O₃ Oxides, etc.
HfB₂ , ZrB₂ , LaB ₆ , CeB₆ , YB_Four , G
dB_Four Boride such as TiC, ZrC, HfC, TaC,
Carbides such as SiC, WC, TiN, ZrN, HfN, etc.
Suitable among nitrides, semiconductors such as Si and Ge, carbon, etc.
It is selected as appropriate.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure has a state in which the fine particles are individually dispersed and arranged, or a state in which the fine particles are adjacent to each other or overlap each other (some fine particles are aggregated). However, it also includes the case where an island-shaped structure is formed as a whole). The particle size of the fine particles is in the range of several angstroms to 1 μm, preferably in the range of 10 angstroms to 200 angstroms.

The electron-emitting portion 005 is composed of a crack having a high resistance formed in a part of the conductive thin film 004, and depends on the film thickness, film quality, material of the conductive thin film 004 and a method such as energization forming described later. Becomes Electron emission part 005
In some cases, conductive particles having a particle diameter of 1000 angstroms or less may be contained in the inside. The conductive fine particles contain some or all of the elements of the material forming the conductive thin film 004. The electron emitting portion 005 and the conductive thin film 004 in the vicinity thereof may contain carbon or a carbon compound.

Next, the vertical surface conduction electron-emitting device will be described. FIG. 7 is a schematic view showing an example of the vertical surface conduction electron-emitting device of the present invention.

In FIG. 7, the same parts as those shown in FIG. 6 are designated by the same reference numerals as those shown in FIG. Reference numeral 21 is a step forming portion. Substrate 001, device electrodes 002 and 003, conductive thin film 004, electron emission portion 005
Can be made of the same material as in the case of the planar surface conduction electron-emitting device described above. The step forming portion 21
SiO formed by vacuum deposition method, printing method, sputtering method, etc.
It can be composed of an insulating material such as ₂ . The film thickness of the step forming portion 21 corresponds to the device electrode interval L1 of the flat surface conduction electron-emitting device described above, and can be set in the range of several thousand angstroms to several tens of μm. This film thickness is
It is set in consideration of the manufacturing method of the step forming portion and the voltage applied between the element electrodes, but is set to several hundred angstroms to several μm.
Is preferred.

The conductive thin film 004 is composed of the device electrodes 002 and 0.
03 and the step forming portion 21, the device electrodes 002, 0
It is laminated on 03. Although the electron emitting portion 005 is formed in the step forming portion 21 in FIG. 7, the shape and position are not limited to this, depending on the forming conditions, forming conditions, and the like.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, and one example thereof is schematically shown in FIG.

An example of the manufacturing method will be described below with reference to FIGS. 6 and 8. Also in FIG. 8, the same parts as those shown in FIG. 6 are designated by the same reference numerals as those shown in FIG. 1) The substrate 001 is thoroughly washed with a detergent, pure water, an organic solvent, etc., and after the element electrode material is deposited by a vacuum deposition method, a sputtering method, etc., the element electrode 002 is formed on the substrate 001 by, for example, a photolithography technique. , 003 are formed (FIG. 8A). 2) An organic metal solution is applied to the substrate 001 provided with the device electrodes 002 and 003 to form an organic metal thin film. As the organometallic solution, a solution of an organometallic compound whose main element is the metal of the conductive thin film 004 described above can be used. The organic metal thin film is heat-fired and patterned by lift-off, etching or the like to form a conductive thin film 004 (FIG. 8B). Although the method of applying the organic metal solution has been described here, the method of forming the conductive thin film 004 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method is used. Method, spinner method, etc. can also be used. 3) Subsequently, a forming process is performed. As an example of this forming processing method, a method based on energization processing will be described. When electric power is applied between the device electrodes 002 and 003 by using a power source (not shown), an electron emitting portion 005 having a changed structure is formed at a portion of the conductive thin film 004 (FIG. 8C).
According to the energization forming, the conductive thin film 004 is locally formed with a structurally changed portion such as destruction, deformation or alteration. This portion becomes the electron emitting portion 005. FIG. 9 shows an example of the voltage waveform of energization forming.

The voltage waveform is preferably a pulse waveform. For this, the method shown in FIG. 9 (a) in which a pulse having a constant pulse peak value is continuously applied and the method shown in FIG. 9 (b) in which a voltage pulse is applied while increasing the pulse peak value There is.

In FIG. 9A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. Normally, T1 is set in the range of 1 microsecond to 10 milliseconds, and T2 is set in the range of 10 microseconds to 100 milliseconds. The peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens of minutes. The pulse waveform is not limited to the triangular wave, and a desired waveform such as a rectangular wave can be adopted.

T1 and T2 in FIG. 9 (b) are shown in FIG.
It can be similar to that shown in (a). The peak value of the triangular wave (peak voltage during energization forming) can be increased by, for example, about 0.1 V step. The end of the energization forming process can be detected by applying a voltage that does not locally break or deform the conductive thin film during the pulse interval T2 and measure the current. For example, 0.
The element current flowing by applying a voltage of about 1 V is measured, the resistance value is obtained, and when the resistance is 1 M ohm or more, the energization forming is terminated.

4) It is preferable that an activation treatment is applied to the element which has been formed. By performing the activation process, the device current If and the emission current Ie are significantly changed. The activation treatment can be performed, for example, in an atmosphere containing a gas of an organic substance, by repeating application of a pulse as in the energization forming. This atmosphere can be formed by using the organic gas remaining in the atmosphere when the inside of the vacuum container is evacuated by using, for example, an oil diffusion pump or a rotary pump, and is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of a suitable organic substance into a vacuum. The preferable gas pressure of the organic substance at this time is different depending on the form of application, the shape of the vacuum container, the type of the organic substance, and the like, and is appropriately set depending on the case. Suitable organic substances include alkanes, alkenes, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxylic acids, organic acids such as sulfonic acids, and the like. Specific examples include C, methane, ethane, propane, etc.
saturated hydrocarbon represented by _n H _{2n + 2} , ethylene, propylene and the like unsaturated hydrocarbon represented by a composition formula such as C _n H _2n , benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, Methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid, etc. can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie are generated.
However, it changes significantly. The termination of the activation process is determined while measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse crest value, etc. are set appropriately.

Carbon or carbon compound means HOPG
(Highly Oriented Pyrolytic Graphite), PG (Pyrol
graphite such as ytic Graphite), GC (Glassy Carbon), etc. (HOPG is graphite having a nearly perfect crystal structure, PG is graphite with a crystal grain of about 200 angstroms and the crystal structure is slightly disordered, and GC has 20 crystal grains. It refers to a crystal structure having a greater degree of disorder in the order of angstroms.), Amorphous carbon (amorphous carbon and carbon containing a mixture of amorphous carbon and the graphite microcrystals),
The film thickness is preferably 500 angstroms or less, and more preferably 300 angstroms or less.

5) Electron-emitting element obtained through the activation process
The child is preferably subjected to a stabilizing treatment. This process is true
The partial pressure of the organic substance in the empty container is 1 × 10^-8less than torr
Lower, preferably 1 x 10^-Ten It's better to do below torr
Yes. The pressure in the vacuum vessel is 10 ^-6.5-10^-7torr
Preferably 1 × 10^-8It is preferably torr or less. true
The vacuum exhaust device that exhausts the empty container is
Oil is used to prevent the oil from affecting the characteristics of the device.
It is preferable to use one that is not used. Specifically soap
Vacuum pumps such as ion pumps and ion pumps
be able to. Furthermore, when exhausting the inside of the vacuum container,
By heating the entire vacuum container, the inner wall of the vacuum container and the electron-emitting device
It is preferable to easily exhaust the adsorbed organic substance molecules.
Yes. The vacuum evacuation condition in the heated state at this time is 80
5 hours or more at ~ 200 ℃ is desirable, especially under this condition
Not limited to, the size and shape of the vacuum vessel, electron emission
It changes depending on various conditions such as the structure of the element. The above organic
For measuring the partial pressure of a substance, the mass number is 10 to 2 by a mass spectrometer.
Measurement of the partial pressure of organic molecules consisting of 00 carbon and hydrogen
Then, it is calculated by integrating the partial pressures.

The atmosphere during driving after the stabilization process is preferably maintained at the atmosphere at the end of the stabilization process, but it is not limited to this, and if the organic substance is sufficiently removed, Even if the degree of vacuum itself is slightly lowered, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed, and as a result, the device current If and the emission current I
e is stable. Various arrangements of electron-emitting devices can be adopted. As an example, a large number of electron-emitting devices arranged in parallel are connected at both ends, a large number of electron-emitting devices are arranged (called a row direction), and the electrons are arranged in a direction orthogonal to this wiring (called a column direction). There is a ladder arrangement in which electrons are controlled and driven from the electron-emitting device by a control electrode (also referred to as a grid) arranged above the electron-emitting device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. For example, the other of the electrodes of the plurality of electron-emitting devices arranged in the same column is commonly connected to the wiring in the Y direction. This is a so-called simple matrix arrangement.

First, the simple matrix arrangement will be described in detail below. An electron source substrate obtained by arranging a plurality of electron-emitting devices of the present invention in a matrix will be described with reference to FIG. In FIG. 10, reference numeral 71 is a substrate, 72 is an X-direction wiring, and 73 is a Y-direction wiring. 74 is a surface conduction electron-emitting device, and 75 is a wire connection. The surface conduction electron-emitting device 74 may be either the flat type or the vertical type described above.

The m X-direction wirings 72 are Dx1 and Dx.
2, ..., Dxm, and is composed of a conductive metal or the like formed by using, for example, the printing method as described above. The wiring material, film thickness, and width are appropriately designed. Y-direction wiring 73
Is composed of n wirings Dy1, Dy2, ..., Dyn, and is formed similarly to the X-direction wiring 72. Between these m X-direction wirings 72 and n Y-direction wirings 73,
An interlayer insulating layer (not shown) (see FIG. 1) is provided to electrically separate the two (m and n are both positive integers).

The interlayer insulating layer (not shown) is composed of SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 71 on which the X-direction wiring 72 is formed, 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 72 and the Y-direction wiring 73. Is set. X-direction wiring 72
And the Y-direction wiring 73 are drawn out as external terminals.

A pair of electrodes (not shown) forming the surface conduction electron-emitting device 74 are electrically connected by m X-direction wirings 72, n Y-direction wirings 73 and a connecting wire 75 made of a conductive metal or the like. Has been done.

The material forming the wiring 72 and the wiring 73, the material forming the connecting wire 75, and the material forming the pair of device electrodes may be the same or different in some or all of the constituent elements. Good. These materials are appropriately selected, for example, from the above-mentioned material of the device electrode. When the material forming the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be referred to as an element electrode.

A scanning signal applying means (not shown) for applying a scanning signal for selecting the row of the surface conduction electron-emitting devices 74 arranged in the X direction is connected to the X-direction wiring 72. On the other hand, a modulation signal generating means (not shown) for modulating each column of the surface conduction electron-emitting devices 74 arranged in the Y direction according to an input signal is connected to the Y-direction wiring 73. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

In the above structure, individual elements can be selected and driven independently by using simple matrix wiring.

An image forming apparatus having such a simple matrix arrangement will be described with reference to FIGS. 11, 12 and 13. FIG. 11 is a schematic view showing an example of the display panel of the image forming apparatus. FIG. 12 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 13 is a block diagram showing an example of a drive circuit for displaying according to an NTSC television signal.

In FIG. 11, 71 is an electron source substrate on which a plurality of electron-emitting devices are arranged, 81 is a rear plate to which the electron source substrate 71 is fixed, and 86 is a fluorescent film 84 on the inner surface of a glass substrate 83.
And a metal back 85 are formed on the face plate. Reference numeral 72 denotes a support frame to which a rear plate and a face plate are connected by using frit glass or the like. Reference numeral 88 denotes an envelope, which is fired in the temperature range of 400 to 500 ° C. for 10 minutes or more in the air or nitrogen and sealed.

Reference numeral 74 corresponds to the electron emitting portion in FIG. Reference numeral 72 is an X-direction wiring corresponding to the wiring 3 in FIG. 1, and 73 is a Y-direction wiring corresponding to the wiring 8 in FIG.

The envelope 88 is composed of the face plate 86, the support frame 82, and the rear plate 81 as described above. Since the rear plate is provided mainly for the purpose of reinforcing the strength of the electron source substrate 71, if the electron source substrate itself has sufficient strength, a separate rear plate can be omitted. Therefore, the support frame is directly sealed to the electron source substrate,
You may comprise an envelope with a face plate, a support frame, and an electron source substrate. It is also possible to install a spacer (atmospheric pressure resistant support member) between the face plate and the rear plate to form an envelope having sufficient strength against atmospheric pressure.

FIG. 12 is a schematic view showing the fluorescent film formed on the face plate of FIG. In the case of monochrome, the fluorescent film 84 can be composed of only the fluorescent material. In the case of a color fluorescent film, it can be composed of a black member 91 called a black stripe or a black matrix and a fluorescent substance 92 depending on the arrangement of the fluorescent substances. In the case of color display, the purpose of providing the black stripes and the black matrix is to make the mixed portions between the respective phosphors 92 of the three primary color phosphors black so as to make the color mixture inconspicuous and to contrast due to external light reflection. It is to suppress the decrease of.

As a method for applying the phosphor to the glass substrate 83 shown in FIG. 11, a precipitation method, a printing method or the like can be adopted regardless of monochrome or color. On the inner surface side of the fluorescent film 84,
Usually, a metal back 85 is provided. The purpose of providing the metal back is to improve the brightness by specularly reflecting the light toward the inner surface side of the light emission of the phosphor toward the face plate 86 side, and to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from damage due to collision of negative ions generated in the envelope. 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 using vacuum deposition or the like.

A transparent electrode may be provided on the face plate 86 outside the fluorescent film (on the side of the glass substrate 83) in order to further increase the conductivity of the fluorescent film 84.

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

The image forming apparatus shown in FIG. 11 is manufactured, for example, as follows. The envelope 88 is exhausted through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating, as in the above-described stabilization process, and is 1 × 10 ⁻⁷ torr.
After creating an atmosphere with a sufficiently low degree of vacuum of organic substances,
It is sealed. A getter process may be performed to maintain the degree of vacuum after the envelope 88 is sealed. This is to heat the getter arranged at a predetermined position (not shown) in the envelope 88 by heating using resistance heating or high frequency heating immediately before or after the envelope 88 is sealed. Then, it is a process of forming a vapor deposition film. Getter is usually Ba
Etc. are the main components, and the vacuum degree of, for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ torr is maintained by the adsorption action of the vapor deposition film.

Next, a configuration example of a drive circuit for performing television display based on an NTSC television signal on a display panel constructed by using an electron source having a simple matrix arrangement will be described with reference to FIG. . In FIG. 13, 101 is a display panel, 102 is a scanning circuit, 103 is a control circuit, and 104 is a shift register. Reference numeral 105 is a line memory, 106 is a synchronizing signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Dox1 to Dox1.
oxm, terminals Doy1 to Doyn, and high-voltage terminal Hv
It is connected to an external electric circuit via. Terminal Dox1
Scanning for sequentially driving row-by-row (N-elements) electron sources provided in the display panel, that is, surface-conduction electron-emitting device groups matrix-wired in a matrix of M rows and N columns. A signal is applied.

A modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals Doy1 to Doyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 k [V] from the DC voltage source Va, which is sufficient to excite the phosphor into the electron beam emitted from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

The scanning circuit 102 will be described. The circuit is provided with M switching elements inside (schematically shown by S1 to Sm in the figure). Each switching element is the output voltage of the DC voltage source Vx or 0.
One of [V] (ground level) is selected and electrically connected to the terminals Dox1 to Doxm of the display panel 101. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs.

In the case of this example, the DC voltage source Vx is an electron emission threshold value which is a drive voltage applied to an element which is not scanned on the basis of the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output a constant voltage that is less than or equal to the voltage.

The control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on an image signal input from the outside. The control circuit 103, based on the synchronization signal Tsync sent from the synchronization signal separation circuit 106, outputs Tscan, Tsft, and Tm to each unit.
Each ry control signal is generated.

The sync signal separation circuit 106 is a circuit for separating a sync signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The sync signal separated by the sync signal separation circuit 106 is composed of a vertical sync signal and a horizontal sync signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. The DATA signal is input to the shift register 104.

The shift register 104 is for serially / parallel-converting the DATA signals serially input in time series for each line of an image, and is based on the control signal Tsft sent from the control circuit 103. Works. (That is, it can be said that the control signal Tsft is the shift clock of the shift register 104). The serial / parallel converted image data for one line (corresponding to driving data for N electron emission elements) is output from the shift register 104 as N parallel signals Idl to Idn.

The line memory 105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Idl to Idn in accordance with the control signal Tmry sent from the control circuit 103. The stored contents are output as I'dl to I'dn,
It is input to the modulation signal generator 107.

The modulation signal generator 107 outputs the image data I ′.
It is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of dl to I′dn, and the output signal is a surface conduction electron in the display panel 101 through terminals Doy1 to Doyn. Applied to the emitting element.

The electron-emitting device of the present invention has the following basic characteristics with respect to the emission current Ie. That is, the electron emission has a clear threshold voltage Vth, and the electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold value, the emission current also changes according to the change in the voltage applied to the device. Therefore, when a pulsed voltage is applied to this element, for example, when a voltage below the electron emission threshold is applied, no electron emission occurs, but when a voltage above the electron emission threshold is applied. Emits an electron beam. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. Further, it is possible to control the total amount of charges of the electron beam output by changing the pulse width Pw. Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device according to the input signal. When carrying out the voltage modulation method, as the modulation signal generator 107, a circuit of the voltage modulation method is used that generates a voltage pulse of a fixed length and appropriately modulates the peak value of the pulse according to the input data. be able to.

In carrying out the pulse width modulation method,
As the modulation signal generator 107, it is possible to use a circuit of a pulse width modulation system that generates a voltage pulse having a constant crest value and appropriately modulates the width of the voltage pulse according to input data.

The shift register 104 and the line memory 10
The digital signal type 5 and the analog signal type 5 can be adopted. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separation circuit 106 into a digital signal, which may be provided with an A / D converter at the output portion of 106. In connection with this, the line memory 10
Depending on whether the output signal of 5 is a digital signal or an analog signal,
The circuit used for the modulation signal generator 107 is slightly different. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 107 is provided with, for example, a D / A
A conversion circuit is used, and an amplification circuit or the like is added if necessary.
In the case of the pulse width modulation method, the modulation signal generator 107 includes
For example, a circuit in which a high-speed oscillator and a counter that counts the number of waves output from the oscillator and a comparator that compares the output value of the counter with the output value of the memory are used. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 107 may be an amplifier circuit using an operational amplifier or the like, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VCO) can be adopted, and an amplifier for voltage amplification up to the drive voltage of the surface conduction electron-emitting device can be added if necessary.

In the image forming apparatus of the present invention having such a structure, each of the electron-emitting devices has a terminal Do outside the container.
Electrons are emitted by applying a voltage via x1 to Doxm and Doy1 to Doyn. High voltage terminal H
A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via v to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 to emit light, and an image is formed.

The configuration example of the image forming apparatus described here is an example, and various modifications can be made based on the technical idea of the present invention. As for the input signal, the NTSC system is mentioned, but the input signal is not limited to this, and PAL, SE
A CAM system, etc., or a TV with more scanning lines than this
Signal (for example, high-quality T including MUSE method)
V) method can also be adopted.

[0062]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Example 1 This example will be described with reference to the schematic diagrams of FIGS. 3 (a) to 3 (f) and FIGS. 4 (g) to 4 (i). Vertical x horizontal = 3 for simplicity
Only the region of × 3 is shown. In the figure, 2 is a conductive thin film uniformly formed on a blue glass substrate (not shown), 3 is a wiring formed on the conductive thin film 2, and 4 is the thin film for processing the conductive thin film 2 into a desired shape. Photoresist applied onto 2; 5 and 6 are element electrodes formed by processing the conductive thin film 2; 7 is an insulating layer formed orthogonal to the wiring 3; 8 is formed on the insulating layer 7; In addition, the wiring is formed so as to have a protruding portion that is connected to the device electrode 6. First, as a conductive thin film 2 on a soda-lime glass substrate, a film is formed by depositing Ti by 8 [nm] and sputtering Pt by 40 [nm] by a sputter deposition method (FIG. 3A). By screen printing on the conductive thin film 2 200 [[mu] m] the width of the wiring 3 of the pattern 1 is formed using a Ag paste [m m] Pitch, dried, to prepare a wire 3 through the baking step (Fig. 3
(B)). A photoresist 4 is applied to the exposed portion of the conductive thin film 2 on this substrate to form a photoresist layer (FIG. 3C). After aligning the photomask on which the desired element shape is drawn with the substrate so that the photoresist 4 is exposed to the desired element electrode position and shape, the photoresist 4 is exposed and developed (see FIG. Three
(D)). Excess portions other than the patterned photoresist 4 and the wiring 3 are removed by dry etching (FIG. 3E), and the photoresist 4 is peeled off to obtain device electrodes 5 and 6 with a gap interval of 20 [μm] ( Figure 3
(F)). 40 striped so as to be orthogonal to the wiring 3.
The insulating layer 7 having a width of 0 [μm] is formed with a glass paste at a pitch of 1 [mm], and is dried and baked to complete the process (FIG. 4G). The insulating layer 7 is subjected to the same process again to increase the film thickness. Wirings 8 having a width of 350 [μm] except for the protrusions are formed at a pitch of 1 [mm] on the insulating layer 7 in the same manner as the wirings 3. At this time, the protruding portion of the wiring 8 is formed so as to be connected to the device electrode 6 (FIG. 4 (h)). A conductive thin film 9 for forming an electron emitting portion is formed between the device electrodes 5 and 6. The formation is carried out by spin-coating the organic palladium solution on the electron source substrate on which the matrix wiring has been formed with a spinner and baking at 300 ° C. for 10 minutes,
Patterning is performed as shown in FIG. 4I using a photolithography method. This completes the fabrication of the electron source substrate. Wiring 3 and wiring 8 of this electron source substrate were sequentially selected and inspected for leaks, etc., but no abnormality was found at all.

[Embodiment 2] Next, an example in which an image forming apparatus is constituted by using the electron source substrate prepared as described above,
This will be described with reference to FIG. A face plate 86 having a metal back formed on the phosphor screen is arranged 5 mm above the electron source substrate 31 on which a large number of surface conduction electron-emitting devices before forming are disposed via a support frame 82. Frit glass was applied to the joint portion of the electron source substrate, and baked at 450 ° C. for 10 minutes in the air to seal the substrate. In FIG. 5, 3 and 8 are wirings. In the case of monochrome, the fluorescent film 84 is made of only a fluorescent material, but in this embodiment, the fluorescent material employs a stripe-shaped black member (see FIG. 12A, hereinafter black stripe), and a black stripe is formed first. Then, each phosphor was applied to the gap to prepare a phosphor film. As the material of the black member, a material having graphite as a main component, which is commonly used, was used. A slurry method was used to apply the phosphor to the substrate. A metal back 85 is usually provided on the fluorescent film. The metal back was produced by performing a smoothing treatment (usually called filming) on the inner surface of the fluorescent film after producing the fluorescent film, and then vacuum-depositing Al. The face plate may be provided with a transparent electrode (not shown) between the fluorescent film and the substrate in order to further increase the conductivity of the fluorescent film, but in this embodiment, sufficient conductivity can be obtained only by using a metal back. I omitted it because it was created. In the case of the above-mentioned sealing, in the case of a color, since the phosphors of the respective colors and the electron-emitting devices have to correspond to each other, 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, through the upper wiring and the lower wiring extending outside the container, A voltage was applied between the device electrodes of the electron-emitting device, and the thin film for forming the electron-emitting part was energized (forming process) to form an electron-emitting part. The voltage waveform of the forming process is shown in FIG.
In FIG. 9A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1 ms and T2 is 1.
0 ms, the peak value of the triangular wave (peak voltage during forming) is 14 V, and the forming process is about 1 × 10 ^-6
It was performed for 60 seconds under a vacuum atmosphere of [torr]. Next, an exhaust pipe (not shown) was heated by a gas burner at a degree of vacuum of about 10 ⁻⁶ [torr] to weld and seal the envelope. Finally, a getter process was performed in order to maintain the degree of vacuum after sealing. This is a heating method such as resistance heating or high-frequency heating immediately before or after sealing, and a getter arranged at a predetermined position (not shown) in the image forming apparatus is heated to form a vapor deposition film. Processing. The getter usually has Ba or the like as a main component, and due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ [to
The vacuum degree of [rr] is maintained. In the image forming apparatus of the present invention completed as described above, the scanning signal and the modulation signal are applied to each surface conduction electron-emitting device through the upper wiring and the lower wiring by the signal generating means (not shown). , Electrons are emitted, and a high voltage of 5 kV or more is applied to the metal back through a high voltage terminal (not shown) extending from the metal back to the outside of the vacuum container, and the electron beam is accelerated to collide with the fluorescent film to excite and emit light. As a result, when an image was displayed, a good image was obtained and there was no non-light emitting portion.

[0064]

According to the present invention, the lower distribution <br/> line initially formed, since Ru is formed on a common element electrodes, even after the thermal process adhesion of the wiring material and the device electrode material Since the wiring on the common element electrode does not shrink even after the heating process, it is possible to form a pattern with high accuracy. At the same time, the wiring film is unlikely to recede and leave a residue. Even if a slight receding occurs and the residue remains, the adhesiveness is good and the residue moves to adversely affect the device. Never.

The present invention is particularly effective when the wiring is formed by printing, particularly by using a thick film printing method such as screen printing and coating and baking. Since the width of the wiring on the common element electrode is less likely to shrink during firing, it is possible to form a pattern having a line width almost as designed. At the same time, it is unlikely that the edge of the wiring film recedes and the residue remains. Even if a slight receding occurs and the residue remains, the adhesiveness is good and the residue moves to adversely affect the element. There is nothing to give.

Further, according to the present invention, if the pattern of the element electrode is formed after the wiring is first formed on the conductive thin film by screen printing or the like, the relative positional accuracy of the element electrode and the wiring is extremely improved. It is possible to improve the assembly accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing wiring portions and element electrodes of an image forming apparatus of the present invention.

FIG. 2 is a diagram showing an example of a manufacturing method of the present invention.

FIG. 3 is a process drawing showing an example of a method for manufacturing an image forming apparatus of the present invention.

FIG. 4 is a process chart showing an example of a method for manufacturing an image forming apparatus of the present invention.

FIG. 5 is an example of an image forming apparatus of the present invention.

6A and 6B are a schematic plan view and a cross-sectional view showing the configuration of a planar surface conduction electron-emitting device.

FIG. 7 is a schematic view of a vertical surface conduction electron-emitting device.

FIG. 8 is a schematic view showing a method of manufacturing a surface conduction electron-emitting device.

FIG. 9 is a schematic diagram showing an example of a voltage waveform in an energization forming process that can be adopted when manufacturing a surface conduction electron-emitting device.

FIG. 10 is a schematic view showing an example of a matrix arrangement type electron source substrate of the present invention.

FIG. 11 is a schematic view showing an example of a display panel of the image forming apparatus of the present invention.

FIG. 12 is a schematic view showing an example of a fluorescent film.

FIG. 13 is a block diagram showing an example of a drive circuit for displaying on an image forming apparatus in accordance with an NTSC television signal.

FIG. 14 is a schematic view of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

1 Substrate 2 Conductive thin film 3 Wiring 4 Photoresist 5 Element electrode 6 Element electrode 7 Insulating layer 8 Wiring 9 Electron emitting portion forming conductive thin film 001 Substrate 002 Element electrode 003 Element electrode 004 Conductive thin film 005 Electron emitting portion 72 X direction wiring 73 Y Directional wiring 21 Step forming portion 31 Electron source substrate 71 Electron source substrate 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 88 Envelope 91 Black member 92 Fluorescent Body 101 Display panel 102 Scanning circuit 103 Control circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator Vx, Va DC voltage source 110 Electron source substrate 111 Electron emission element 112 Dx1 to Dx10 are the electron emission elements Common wiring for wiring 120 Opening 122 for head electrode 121 electrons pass through Dox1, Dox2, G1 is connected to the vessel terminals 123 grid electrodes 120 made of · · · Doxm, G
2, ... Gn external terminal made of Gn

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Claims (3)

(57) [Claims] 1. A plurality of electron-emitting devices each having a conductive thin film having an electron-emitting portion and a pair of device electrodes are arranged in a matrix, and a plurality of lower electrodes connected to the device electrodes for driving the electron-emitting devices. Wiring and multiple upper wirings are separated by an insulating layer
In the method of manufacturing an electron source substrate formed by intersecting with each other , a thin film is formed on the entire surface of the substrate, and then the composite film is formed on the thin film.
A plurality of lower wirings, and patterning the thin film to form a pair of device electrodes.
The element electrode that constitutes one of the
Exist at the front and at the part facing the one element electrode.
The pair of device electrodes should be arranged so that a part of them protrudes from the wiring below.
On the other hand the forming step and, a method for manufacturing including electronic source substrate to form a common element electrode in the direction of the lower wire of the electrode. 2. The lower wiring and the upper wiring are formed by coating and baking by screen printing.
1. The method for manufacturing the electron source substrate according to 1 . 3. A method of manufacturing an image forming apparatus, comprising a step of manufacturing an electron source substrate by the manufacturing method according to claim 1 .