JP3710273B2 - Electron source and image forming apparatus manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron source in which a large number of electron-emitting devices are arranged, an image forming apparatus such as a display device and an exposure apparatus configured using the electron source, and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, two types of electron-emitting devices, known as a thermionic electron-emitting device and a cold cathode electron-emitting device, are known. Cold cathode electron-emitting devices include field emission type (hereinafter referred to as “FE type”), metal / insulating layer / metal type (hereinafter referred to as “MIM type”), surface conduction electron-emitting device, and the like. .
[0003]
Examples of surface conduction electron-emitting devices include M.I. I. Elinson, Radio Eng. Electron Phys. 10, 1290 (1965) and the like.
[0004]
The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel to the film surface. As a typical configuration example of this surface conduction electron-emitting device, for example, Japanese Patent Laid-Open No. 7-235255 discloses a device using a metal thin film such as Pd, and the device configuration is schematically shown in FIG. Shown in In the figure, 1 is a substrate, 2 and 3 are element electrodes. Reference numeral 4 denotes a conductive film made of a metal oxide thin film such as Pd, and an electron emission portion 5 is formed in a part thereof by an energization process called energization forming described later.
[0005]
In the energization forming, an electron emission portion 5 including a crack in which a voltage is applied to both ends of the conductive film 4 to locally break, deform or alter the conductive film 4 to bring it into an electrically high resistance state. Is a process of forming
[0006]
Further, in order to improve the electron emission characteristics, a process called “activation” is performed as described later, and a film made of carbon and / or a carbon compound is formed on the electron emission portion 5 or in the vicinity of the electron emission portion ( Carbon film) may be formed.
[0007]
The above activation treatment can be performed by a method in which a voltage is applied to both ends of the conductive film 4 in an atmosphere containing an organic substance, and a carbon film is deposited on the electron emission portion 5 or further around it.
[0008]
The above-described surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because of its simple structure and easy manufacture. Therefore, various applications for utilizing this feature have been studied. For example, utilization to image forming apparatuses, such as a charged beam source and a display apparatus, is mentioned.
[0009]
An example in which a large number of surface conduction electron-emitting devices are arranged and formed will be described in detail later, but surface conduction electron-emitting devices are arranged in parallel, and both ends of each device are connected by wiring (also referred to as common wiring). Examples thereof include an electron source in which a large number of connected rows are arranged (for example, Japanese Patent Application Laid-Open No. 64-031332, Japanese Patent Application Laid-Open No. 1-283749, Japanese Patent Application Laid-Open No. 2-257552, etc.).
[0010]
In particular, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystals have been used in place of CRTs. However, since they are not self-luminous, they must have a backlight or the like. There is a problem, and the development of a self-luminous display device has been desired. As a self-luminous display device, there is an image forming apparatus which is a display device in which an electron source in which a large number of surface conduction electron-emitting devices are arranged and a phosphor that emits visible light by electrons emitted from the electron source. (For example, US Pat. No. 5,066,883).
[0011]
In an image forming apparatus using an electron source in which a large number of surface conduction electron-emitting devices as described above are arranged, the facing distance between the electron source substrate and the phosphor-containing substrate can be shortened. Unlike conventional CRTs, A thin device can be constructed.
[0012]
[Problems to be solved by the invention]
However, conventionally, in the activation process, which is one manufacturing process of the electron source, depending on the type of organic substance, the electron emission characteristics (electron emission characteristics) of the obtained electron-emitting device are obtained when the partial pressure of the organic substance is large Amount, electron emission efficiency, etc.) may decrease, and the pressure in the vacuum container containing the organic substance is 1 × 10^-2The pressure was set to about Pa or lower.
[0013]
On the other hand, when manufacturing an image forming apparatus for the purpose of image display as described above, a substrate having a phosphor is opposed to an electron source substrate in which a large number of surface conduction electron-emitting devices are arranged on the substrate, and these are made thin. In some cases, after the device is installed in an envelope having a very narrow space, an element forming process and an activation process are performed on the electron source substrate. However, when the above-described organic substance is introduced into a thin envelope having a very narrow space, the electron source substrate activation process is performed as described below. However, it is difficult to perform uniform activation.
[0014]
In other words, the conductance of gas is small in a thin envelope with a narrow internal space. When gas is introduced into such an envelope under high vacuum, the gas itself may not enter the envelope. The difference in the pressure (partial pressure) of the organic material is likely to occur depending on the distance from the gas supply port and the exhaust port provided in the envelope, and the concentration of the organic material is likely to vary depending on the location on the electron source substrate. In some cases, the elements on the electron source substrate cannot be activated uniformly.
[0015]
When non-uniform activation is performed for each electron-emitting device on the electron source substrate in this way, the electron emission characteristics vary for each electron-emitting device, and in an image forming apparatus using such an electron source, a display image is displayed. There is a problem of uneven brightness.
[0016]
An object of the present invention is to provide an electron source having a plurality of electron-emitting devices having uniform electron emission characteristics, and further to provide an image forming apparatus capable of forming a higher quality image. is there.
[0017]
[Means for Solving the Problems]
The configuration of the present invention made to achieve the above object is as follows.
[0018]
  That is, a first aspect of the present invention is a method of manufacturing an electron source comprising a plurality of electron-emitting devices having a conductive film including an electron-emitting portion between a pair of device electrodes in an envelope having an internal space.
  At least an organic substance inside the envelopeAnd inert gasAnd an activation step of depositing carbon or / and a carbon compound on at least the electron emission portion by applying a voltage between the device electrodes after sealing the gas containing the gas so as to be in the pressure of the viscous flow region, Organic matterAnd inert gasA method for producing an electron source is characterized in that a gas containing a gas is convected inside the envelope.
[0019]
  According to a second aspect of the present invention, there is provided a method of manufacturing an electron source comprising a plurality of electron-emitting devices having a conductive film including an electron-emitting portion between a pair of device electrodes on a substrate.
  An envelope that temporarily forms a space cut off from the outside air is provided on the base on which the conductive film including the element electrode and the electron emission portion is formed, and at least an organic substance is provided in the space.And inert gasAnd an activation step of depositing carbon or / and a carbon compound on at least the electron emission portion by applying a voltage between the device electrodes after sealing the gas containing the gas so as to be in the pressure of the viscous flow region, Organic matterAnd inert gasA method for producing an electron source is characterized in that a gas containing a gas is convected in the space.
[0020]
  The manufacturing method of the first and second electron sources according to the present invention is further characterized in that “the organic substance in the envelope is provided by giving a temperature distribution to the envelope.And inert gasConvection of gas containing
  "The organic substance inside the envelopeAnd inert gas, Convection of the gas containing the organic substance by generating ions in the gas containing, and applying an electromagnetic force to the ions. "
  "The organic substance inside the envelopeAnd inert gasThe total pressure of the gas containing is 100 Pa or more ",
  "The electron-emitting device is a surface conduction electron-emitting device "
Is also included.
[0023]
  In addition, the first of the present invention3An electron source including a plurality of electron-emitting devices each having a conductive film including an electron-emitting portion between a pair of device electrodes in an envelope having an internal space, and irradiation of an electron beam emitted from the electron source In the manufacturing method of an image forming apparatus comprising an image forming member for forming an image by the method, the electron source is manufactured by the first or second method of the present invention. is there.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment of the present invention will be shown.
[0026]
In the present invention, for example, an electron-emitting device described in JP-A-7-235255 can be suitably used, and the basic configuration is roughly classified into a planar type and a vertical type.
[0027]
A planar electron-emitting device refers to a device having a structure in which device electrodes are formed on the same surface, and a vertical electron-emitting device is a device in which device electrodes are positioned above and below via an insulating layer, An element having a structure in which a conductive film is formed on the side surface of the insulating layer. Hereinafter, only the planar electron-emitting device will be outlined.
[0028]
1A and 1B are schematic views showing a configuration example of a planar electron-emitting device used in the present invention. FIG. 1A is a plan view and FIG. 1B is a longitudinal sectional view. In FIG. 1, 1 is a substrate, 2 and 3 are electrodes (element electrodes), 4 is a conductive film, and 5 is an electron emission portion.
[0029]
As the substrate 1, quartz glass, glass with reduced impurity content such as Na, blue plate glass, blue plate glass, SiO 2 by sputtering, etc.₂ A glass substrate laminated with ceramics such as alumina, an Si substrate, or the like can be used.
[0030]
As a material of the device electrodes 2 and 3 facing each other, a general conductive material can be used. The element electrode interval L, the element electrode length W, the shape of the conductive film 4 and the like are designed in consideration of the applied form and the like.
[0031]
Not only the configuration shown in FIG. 1 but also a configuration in which the conductive film 4 and the opposing element electrodes 2 and 3 are stacked in this order on the substrate 1 may be employed.
[0032]
The main materials constituting the conductive film 4 are Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W, Pb, and other metals, PdO, SnO.₂ , In₂ O_Three , PbO, Sb₂ O_Three Oxides such as HfB₂ , ZrB₂ , LaB₆ , CeB₆ , YB_Four , GdB_Four Boride such as TiC, ZrC, HfC, TaC, SiC, and WC, nitride such as TiN, ZrN, and HfN, semiconductor such as Si and Ge, carbon, and the like.
[0033]
In order to obtain good electron emission characteristics, it is preferable to use a fine particle film composed of fine particles for the conductive film 4. The film thickness is appropriately set in consideration of the step coverage to the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, forming conditions described later, and the like. The range is preferable, and the range of 1 nm to 50 nm is more preferable. Its resistance value is 10 for Rs.² Ω / □ -10⁷ A value of Ω / □ is preferred. Note that Rs is a value when the resistance R of a thin film having a width w and a length l is set as R = Rs (l / w). The fine particle film described here is a film in which a plurality of fine particles are aggregated, and the fine structure thereof is 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, Including the case where an island-like structure is formed as a whole). The particle diameter of the fine particles is in the range of several to hundreds of nm, preferably in the range of 1 to 20 nm.
[0034]
The electron emission portion 5 includes a high-resistance crack formed in a part of the conductive film 4 and depends on the film thickness, film quality, material, and a method such as energization forming described later. It will be a thing. There may be a case where conductive fine particles having a particle diameter in the range of several to several tens of nanometers exist inside the electron emission portion 5. The conductive fine particles contain a part or all of the elements of the material constituting the conductive film 4. Further, as a result of the activation process described later, the electron emission portion 5 and the conductive film 4 in the vicinity thereof have carbon and / or a carbon compound.
[0035]
The electron source of the present invention has a plurality of electron-emitting devices as described above on a substrate, and an example of a manufacturing method thereof will be described with reference to FIGS. 2 and 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals.
[0036]
1) Formation of device electrodes
The substrate 1 is sufficiently cleaned using a detergent, pure water, an organic solvent, and the like, and element electrode materials are deposited by a vacuum deposition method, a sputtering method, or the like, and then a plurality of pairs of element electrodes are formed on the substrate 1 using, for example, a photolithography technique. 2 and 3 are formed (FIG. 2A).
[0037]
2) Formation of conductive film
An organometallic solution is applied on the substrate 1 provided with a plurality of pairs of element electrodes 2 and 3 to form an organometallic film. As the organic metal solution, a solution of an organic compound containing the metal of the material of the conductive film 4 as a main element can be used. This organometallic film is heated and baked and patterned by lift-off, etching, or the like to form a conductive film 4 straddling between each pair of element electrodes 2 and 3 (FIG. 2B). Here, the application method of the organic metal solution has been described, but the method of forming the conductive film 4 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, a spinner method, or the like can also be used.
[0038]
3) Forming process
Subsequently, a forming process is performed. A method using energization processing will be described as an example of the forming process. When power is supplied between the element electrodes 2 and 3 from a power source (not shown) in a predetermined vacuum atmosphere, an electron emission portion 5 having a changed structure is formed at a portion of the conductive film 4 (FIG. 2C). According to the energization forming, a region having a structural change such as local destruction, deformation or alteration is formed in the conductive film 4 (generally, it is often in the form of a crack). This part constitutes the electron emission part 5. An example of the voltage waveform of energization forming is shown in FIG.
[0039]
The voltage waveform of energization forming is particularly preferably a pulse waveform. For this purpose, there are a method shown in FIG. 3A in which a pulse having a pulse peak value as a constant voltage is continuously applied, and a method shown in FIG. 3B in which a pulse is applied while increasing the pulse peak value. is there.
[0040]
4) Activation treatment
The element that has finished forming is subjected to a process called an activation process. The activation process means that the device current I_f , Emission current I_e Is a process that changes significantly.
[0041]
The activation step can be performed, for example, by repeating the application of a pulse voltage between the device electrodes 2 and 3 in the same manner as the energization forming in an atmosphere containing an organic substance. A preferable gas pressure of the organic material at this time is appropriately set depending on the case because it varies depending on the form of the element, the shape of the vacuum vessel, the kind of the organic material, and the like.
[0042]
By this activation treatment, carbon or a carbon compound is deposited on the device from an organic substance present in the atmosphere, and the device current I_f , Emission current I_e Will change significantly.
[0043]
Here, the carbon and the carbon compound include, for example, graphite (so-called HOPG, PG, and GC, where HOPG is an almost complete graphite crystal structure, PG is a crystal grain having a crystal structure of about 200 mm and a slightly disturbed crystal structure, GC refers to a crystal grain having a crystal grain size of about 20 mm and further disorder in the crystal structure.), Amorphous carbon (refers to a mixture of amorphous carbon and amorphous carbon and microcrystals of the graphite), The film thickness is preferably in the range of 50 nm or less, and more preferably in the range of 30 nm or less.
[0044]
Suitable organic substances that can be used in the present invention include alkanes, alkenes, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenol, carvone, and sulfonic acid. Organic acids such as methane, ethane, propane, etc._n H_{2n + 2}Saturated hydrocarbon represented by C, ethylene, propylene, acetylene, etc._n H_2nOr C_n H_2n-2Unsaturated hydrocarbons represented by the composition formulas such as benzene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used.
[0045]
In the present invention, the above organic substances may be used alone, or may be mixed and used as necessary. Further, these organic substances may be diluted with other gases that are not organic substances. Hereinafter, the gas containing the organic substance and used in the activation process is referred to as “activation gas”.
[0046]
Since the present invention is characterized in that the activating gas is convected as described later, the total pressure of the activating gas needs to be a gas viscous flow region, and more specifically, 100 Pa or more is preferable. .
[0047]
Although depending on the conditions, when the partial pressure of the organic substance in the activation gas increases, the electron emission characteristics (electron emission amount, electron emission efficiency) of the obtained electron-emitting device may decrease. Therefore, as long as activation is possible, it may be preferable that the partial pressure of the organic substance in the activation gas is low. In that case, it is preferable to use a diluted activation gas.
[0048]
The requirements for the dilution gas include, for example, that it does not react with the organic substance in the activation gas, inhibits the formation reaction of carbon or carbon compound generated in the activation process, or decomposes the formed carbon or carbon compound. For example, don't do it. Examples of the type of gas that can be used as such a dilution gas include inert gases such as nitrogen, argon, and xenon.
[0049]
In the present invention, as voltage application conditions in the activation step, the time change of the voltage value, the direction of voltage application, the waveform, and the like can be appropriately selected according to the situation.
[0050]
Similar to forming, the time change of the voltage value can be performed by a method of increasing the voltage value with time or a method of performing a fixed voltage.
[0051]
Moreover, as shown in FIG. 4, the voltage application direction may be applied only in the same direction (forward direction) as the drive (FIG. 4 (a)), or the forward direction and the reverse direction are changed alternately. May be applied (FIG. 4B). When the voltage is applied alternately, it is considered that a carbon film is formed symmetrically with respect to the crack, which may be preferable.
[0052]
As for the waveform, FIG. 4 shows an example of a rectangular wave, but an arbitrary waveform such as a sine wave, a triangular wave, or a sawtooth wave can be used.
[0053]
The end of the activation process is determined by the device current I_f It can carry out suitably, measuring.
[0054]
5) Stabilization process
The electron-emitting device obtained through such processes is preferably subjected to a stabilization process. This step is a step of exhausting the organic substance in the vacuum vessel (corresponding to an envelope in the present invention). As the vacuum exhaust device for exhausting the vacuum vessel, it is preferable to use a device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, vacuum exhaust apparatuses such as a sorption pump and an ion pump can be used. The partial pressure of the organic component in the vacuum vessel is 1.3 × 10 6 at a partial pressure at which the carbon or carbon compound is not newly deposited.^-6Pa or less is preferable, and further 1.3 × 10^-8Pa or less is particularly preferable. Furthermore, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device can be easily evacuated. The heating conditions at this time are 80 ° C. or higher, preferably 150 ° C. or higher, and it is desirable to perform the treatment for as long as possible. However, the heating conditions are not particularly limited, and the size and shape of the vacuum vessel, the configuration of the electron-emitting device, etc. The conditions are appropriately selected according to these conditions. The pressure in the vacuum vessel must be as low as possible, 1.3 × 10^-FivePa or less is preferable, and further 1.3 × 10^-6Pa or less is particularly preferable.
[0055]
The driving atmosphere after the stabilization process is preferably maintained at the end of the stabilization process, but is not limited to this. If the organic material is sufficiently removed, the degree of vacuum Even if it is somewhat lowered, it can maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, deposition of new carbon or carbon compounds can be suppressed, and H adsorbed on a vacuum vessel or a substrate can be suppressed.₂ O, O₂ Etc., and as a result, the device current I_f , Emission current I_e However, it becomes stable.
[0056]
The basic characteristics of the electron-emitting device constituting the electron source obtained through the above-described steps will be described with reference to FIG.
[0057]
FIG. 5 shows the emission current I of the electron-emitting device constituting the electron source formed according to the present invention._e And element current I_f And element voltage V_f It is the figure which showed typically the relationship. In FIG. 5, the emission current I_e Is the device current I_f Since it is remarkably small compared to, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.
[0058]
As is apparent from FIG. 5, this electron-emitting device has an emission current I._e Has the following three characteristic properties.
[0059]
That is, first, the device has a certain voltage (called a threshold voltage; V in FIG._th) When the above device voltage is applied, the emission current I suddenly increases._e While the threshold voltage V_thIn the following, the emission current I_e Is hardly detected. That is, the emission current I_e Clear threshold voltage V for_thIs a non-linear element.
[0060]
Second, the emission current I_e Is the element voltage V_f The emission current I_e Is the element voltage V_f Can be controlled.
[0061]
Third, the emitted charge is the device voltage V_f Depends on the time to apply. In other words, the amount of charge is the element voltage V_f Can be controlled by applying time.
[0062]
As understood from the above description, the electron-emitting device used in the present invention can easily control the electron-emitting characteristics according to the input signal. By utilizing this property, it is possible to apply to various fields such as an electron source and an image forming apparatus configured by arranging a plurality of electron-emitting devices.
[0063]
In FIG. 5, the element current I_f Is the element voltage V_f In this example, the element current I increases monotonically (MI characteristic)._f Is the element voltage V_f May exhibit voltage controlled negative resistance characteristics (VCNR characteristics) (not shown). These characteristics can be controlled by controlling the aforementioned steps.
[0064]
Next, an image forming apparatus including an electron source in which a plurality of the above-described electron-emitting devices are arranged on a substrate and an image forming member that forms an image by irradiation of an electron beam from the electron source will be described with a specific example. explain.
[0065]
Various arrangements of the electron-emitting devices in the electron source of the present invention can be employed. As an example, a large number of electron-emitting devices arranged in parallel are connected at both ends, and a plurality of rows of electron-emitting devices are arranged (referred to as a row direction), and in a direction perpendicular to the wiring (referred to as a column direction). There is a ladder arrangement in which electrons from the electron-emitting device are controlled and driven by a control electrode (also referred to as a grid) disposed 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 the electrodes of the plurality of electron-emitting devices arranged in the same row is connected in common to the wiring in the X direction. Examples include one in which 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. Such is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.
[0066]
As described above, the surface conduction electron-emitting device to which the present invention can be applied has three characteristics. That is, the emitted electrons from the surface conduction electron-emitting device can be controlled by the peak value and width of the pulse voltage applied between the device electrodes facing each other above the threshold voltage. On the other hand, it is hardly emitted below the threshold voltage. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulse voltage is appropriately applied to each device, a surface conduction electron-emitting device is selected according to the input signal, and the amount of electron emission Can be controlled.
[0067]
Based on this principle, an electron source substrate obtained by arranging a plurality of electron-emitting devices to which the present invention can be applied will be described with reference to FIG.
[0068]
In FIG. 6, 71 is an electron source substrate, 72 is an X direction wiring, and 73 is a Y direction wiring. 74 is an electron-emitting device, and 75 is a connection. The electron-emitting device 74 may be either the above-described planar type or vertical type.
[0069]
The m X-direction wirings 72 are D_x1, D_x2, ..., D_xmAnd can be made of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The wiring material, film thickness, and width are appropriately designed. The Y-direction wiring 73 is D_y1, D_y2, ..., D_ynThe n wirings are formed in the same manner as the X direction wiring 72. An interlayer insulating layer (not shown) is provided between the m X-direction wirings 72 and the n Y-direction wirings 73 to electrically isolate both (m and n are both Positive integer).
[0070]
The interlayer insulating layer (not shown) is formed of SiO formed by vacuum deposition, printing, sputtering, or the like.₂ Etc. 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, so as to withstand the potential difference at the intersection of the X direction wiring 72 and the Y direction wiring 73. Materials and manufacturing methods are set as appropriate. The X direction wiring 72 and the Y direction wiring 73 are drawn out as external terminals, respectively.
[0071]
A pair of device electrodes (not shown) constituting the electron-emitting device 74 are electrically connected to the m X-direction wirings 72 and the n Y-direction wirings 73 by connection lines 75 made of conductive metal or the like. Yes.
[0072]
The materials constituting the wiring 72 and the wiring 73, the material constituting the connection 75, and the material constituting the pair of element electrodes may be the same or partially different from each other in the constituent elements. These materials are appropriately selected from, for example, the above-described element electrode materials. When the material constituting the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be called an element electrode.
[0073]
The X direction wiring 72 is connected to scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 74 arranged in the X direction. On the other hand, the Y-direction wiring 73 is connected to a modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 74 arranged in the Y direction according to an input signal. The drive voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.
[0074]
In the above configuration, individual elements can be selected using the matrix wiring and driven independently.
[0075]
An image forming apparatus constructed using such a simple matrix electron source will be described with reference to FIGS. 7, 8, and 9. FIG. FIG. 7 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 8 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 9 is a block diagram illustrating an example of a driving circuit for performing display in accordance with an NTSC television signal.
[0076]
In FIG. 7, reference numeral 71 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged, 81 denotes a rear plate on which the electron source substrate 71 is fixed, 86 denotes a face having a fluorescent film 84 and a metal back 85 formed on the inner surface of a glass substrate 83. It is a plate. Reference numeral 82 denotes a support frame, and a rear plate 81 and a face plate 86 are joined to the support frame 82 using frit glass having a low melting point or the like. Reference numeral 74 denotes an electron-emitting device as shown in FIG. Reference numerals 72 and 73 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes (not shown) of the electron-emitting device 74.
[0077]
The envelope 88 includes the face plate 86, the support frame 82, and the rear plate 81 as described above. Since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the substrate 71, if the substrate 71 itself has sufficient strength, the separate rear plate 81 can be omitted. That is, the support frame 82 may be directly sealed on the substrate 71, and the envelope 88 may be configured by the face plate 86, the support frame 82, and the substrate 71. On the other hand, by installing a support body (not shown) called a spacer between the face plate 86 and the rear plate 81, an envelope 88 having sufficient strength against atmospheric pressure can be configured.
[0078]
FIG. 8 is a schematic view showing a fluorescent film. In the case of monochrome, the fluorescent film 84 can be composed of only a phosphor. In the case of a color phosphor film, it may be composed of a black conductive material 91 called a black stripe (FIG. 8A) or a black matrix (FIG. 8B) and a phosphor 92 depending on the arrangement of the phosphors. it can. The purpose of providing the black stripe and the black matrix is to make the mixed colors and the like inconspicuous by making the coloration portions between the phosphors 92 of the three primary color phosphors necessary in the case of color display, The purpose is to suppress a decrease in contrast due to light reflection. As a material of the black conductive material 91, a material having conductivity and low light transmission and reflection can be used in addition to a commonly used material mainly composed of graphite.
[0079]
As a method of applying the phosphor on the glass substrate 83, a precipitation method, a printing method, or the like can be adopted regardless of monochrome or color. A metal back 85 is usually provided on the inner surface side of the fluorescent film 84. The purpose of providing the metal back is to improve the brightness by specularly reflecting the light emitted from the phosphor toward the inner surface to the face plate 86 side, to act as an electrode for applying an electron beam acceleration voltage, For example, the phosphor is protected from damage caused by the collision of negative ions generated in the envelope. The metal back can be produced by performing a smoothing process (usually called “filming”) on the inner surface of the phosphor film after the phosphor film is produced, and then depositing Al using vacuum evaporation or the like.
[0080]
The face plate 86 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 84 in order to further increase the conductivity of the fluorescent film 84.
[0081]
When performing the above-described sealing, in the case of a color, it is necessary to associate each color phosphor with the electron-emitting device, and sufficient alignment is essential.
[0082]
An example of a method for manufacturing the image forming apparatus as shown in FIG. 7 will be described below.
[0083]
FIG. 12 schematically shows an outline of an apparatus suitably used in the forming process and the activation process in the manufacturing method of the present invention. The image display device 131 is connected to the vacuum chamber 133 via the exhaust pipe 132 and further connected to the exhaust device 135 via the gate valve 134. In the vacuum chamber 133, a pressure gauge 136, a quadrupole mass analyzer 137, and the like are attached in order to measure the internal pressure and the partial pressure of each component in the atmosphere. Since it is difficult to directly measure the pressure in the envelope 88 of the image display device 131, the pressure in the vacuum chamber 133 is measured to control the processing conditions. A gas introduction line 138 is connected to the vacuum chamber 133 in order to introduce further necessary gas into the vacuum chamber 133 and control the atmosphere. An introduction material source 140 is connected to the other end of the gas introduction line 138, and the introduction material is stored in an ampoule or a cylinder. A gas introduction amount control means 139 is provided in the middle of the gas introduction line 138. As the introduction amount control means 139, specifically, a valve capable of controlling the gas flow rate such as a slow leak valve, a mass flow controller, or the like can be used depending on the type of the introduced substance.
[0084]
If the inside of the envelope 88 is evacuated using the apparatus of FIG. 12, the above-described forming process can be performed. At this time, for example, as shown in FIG. 13, the Y direction wiring 73 is connected to the common electrode 141, and a voltage pulse is simultaneously applied to the element row connected to one of the X direction wirings 72 by the power source 142. Energization forming can be performed. At this time, the conditions such as the shape of the pulse and the determination of the end of the process may be selected according to the above-described method for forming the individual elements. In addition, by sequentially applying (scrolling) a phase-shifted pulse to a plurality of X-direction wirings, elements connected to the plurality of X-direction wirings can be collectively formed. In FIG. 13, reference numeral 143 denotes a current measurement resistor, and 144 denotes a current measurement oscilloscope.
[0085]
After the forming is completed, an activation process, which is the greatest feature of the present invention, is performed. Below, this activation process is explained in full detail.
[0086]
In a thin envelope in which the distance between the face plate 86 and the rear plate 81 is narrow, the conductance of the activated gas is reduced, and the atmosphere of the activated gas is distributed inside the envelope, or it takes time to introduce the activated gas. There was a problem that it took.
[0087]
Conventionally, the activation process includes 1.3 × 10 10 containing an organic substance.^-2It was performed in a high vacuum atmosphere of Pa or less. In this case, in order to prevent fluctuations in the vacuum pressure due to the gas released from the inner surface of the envelope 88 and the change in the opening of the valve for introducing the activated gas, a minute amount is always kept in the evacuated state. It was necessary to keep the activated gas flowing.
[0088]
In the present invention, the activation gas introduced into the envelope is convected in the envelope, so that the uniformity of the activation gas in the envelope is maintained and the activation of the electron-emitting devices on the electron source substrate is maintained. Is performed uniformly.
[0089]
In order to convect the activated gas in the envelope in this way, the total pressure of the activated gas is a gas viscous flow region, and more specifically, 100 Pa or more is preferable.
[0090]
As shown in FIG. 12, the activated gas can be introduced into the envelope 88 through the exhaust pipe 132 via the gas introduction line 138 and the like, and there are several methods for this introduction. For example, after the inside of the envelope is exhausted once, gas introduction is performed (this method is used when there is one exhaust pipe). In the case where there are a plurality of exhaust pipes, it is also possible to flow the activation gas for an appropriate time.
[0091]
When introducing the activation gas, it is preferable to evacuate the envelope 88 in advance in order to suppress as much as possible components (eg, water) that inhibit the activation process. It is more preferable to exhaust while heating the whole.
[0092]
In the present invention, after the activation gas is introduced into the envelope 88 through the vacuum chamber 138, the valve 130 provided between the vacuum chamber 138 and the envelope 88 is closed to surround the activation gas. After sealing in the vessel 88, the activated gas is convected in the envelope 88. Thereby, the convection of the activated gas in the envelope 88 can be performed without being disturbed by the diffusion of the activated gas from the vacuum chamber 138.
[0093]
Examples of the convection method of the activated gas in the production method of the present invention include the following methods.
[0094]
(1). A portion of the envelope 88 is heated or cooled to create a temperature difference in the internal activated gas and cause convection.
[0095]
(2). Ions are generated in the activated gas, the ions are moved by the action of an electric field or a magnetic field, and the activated gas is convected by being dragged by the movement of the ions.
[0096]
FIG. 14 is a principle diagram of the convection method using the temperature difference (1).
[0097]
FIG. 14A shows a heater 161 that heats either the face plate 86 or the rear plate 81 (rear plate 81 in the figure) of the envelope 88 from below to the line. It is preferable to avoid the electron source substrate 71 at a place where the envelope 88 is heated or cooled. This is to prevent the activation process from being newly affected by the temperature difference of the electron source substrate 71.
[0098]
However, as shown in FIG. 14B, a number of similar heaters 161 can be arranged on the main line, and the activated gas can be convected more efficiently at several locations. In this case, it is preferable to divide the activation process according to the location of the heater and take measures such as heating a heater other than the vicinity of the element that is being activated.
[0099]
The temperature difference applied to the envelope 88 is preferably 10 ° C. or higher. If this temperature difference is small, the convection of the activated gas tends to be insufficient in the envelope. On the other hand, it is necessary that the envelope is not destroyed by thermal strain generated in the envelope due to a local temperature difference, and this determines the upper limit of the temperature difference applied to the envelope. The relationship between strain and fracture is determined by the size of the envelope and the type of material making up the envelope. In general, in the case of an envelope using a glass material and a frit glass having a thermal expansion coefficient matched with a glass material of a size of about A4 size, a temperature difference of 5 ° C. or more per 1 mm is not included in the envelope. The envelope needs to be heated.
[0100]
15 and 16 are principle diagrams for convection of the activated gas by moving the ions by applying an electric field or a magnetic field to the ions existing in the activated gas of (2).
[0101]
15 and 16, the ions 162, 175, and 176 are generated in the activated gas by introducing the activated gas into the envelope and ionizing a part of the activated gas. it can. As a method of ionizing the activated gas, for example, a method of discharging the counter electrodes 163, 164, 170, 171, 172, and 173 provided inside the envelope 88 by applying a high frequency from the power sources 167 and 174 may be used. is there.
[0102]
Although FIG. 15 shows an example in which the electrodes 165 and 166 that act on the electric field E are provided on the inner side of the support frame 82 that constitutes the envelope 88, the present invention is not limited to this configuration.
[0103]
In FIG. 16, the activated gas can be convected by moving the ions 175 and 176 by applying an alternating magnetic field H to the ions 175 and 176 existing in the activated gas. That is, when an alternating magnetic field H is applied, an eddy current I is induced so as to cancel the magnetic field. Since this eddy current I is the movement of ions in the activated gas, the activated gas can be convected by this movement. 16A is a cross-sectional view, and FIG. 16B is a perspective view.
[0104]
Although FIG. 16 shows an example in which the coil 169 for applying the magnetic field H is provided on the outer periphery of the support frame 82 constituting the envelope 88, the present invention is not limited to this configuration.
[0105]
In the manufacturing method of the present invention, the activation gas in the envelope 88 is kept uniform by convection of the activation gas in the envelope 88 as described above, and the activation of each electron-emitting device is maintained. A plurality of electron-emitting devices having uniform electron-emitting characteristics can be formed. Further, unlike the conventional activation process performed in the high vacuum region, the total pressure of the activation gas can be set large (for example, even at atmospheric pressure), so that the surroundings can be provided without using a high vacuum device. The activation material can be stably introduced into the container 88, and the electron source and the image forming apparatus can be manufactured by a simpler process.
[0106]
In the present invention, as shown in FIG. 17, a means for removing a component that inhibits the activation process may be provided in the convection path of the activation gas. Examples of the component that inhibits the activation process include water. By providing a means for removing water in the convection path of the activation gas, the characteristics of the electron-emitting device obtained in the activation process can be improved. . As the water removing agent for removing this water, for example, inorganic hydrochloric acid, phosphorus pentoxide and the like can be used. As shown in FIG. 17, these moisture removing agents are not dispersed in the envelope 88 and are held in a moisture removing body 181 made of, for example, a metal mesh container or the like, or inert such as alumina. The surface of the carrier or the envelope 88 can be coated. 17A is a sectional view, and FIG. 17B is a partially cutaway perspective view.
[0107]
By applying a voltage to each electron-emitting device formed on the electron source substrate 71 in the atmosphere in the envelope 88 in which the activation gas is uniformly introduced as described above, carbon or a carbon compound, or A mixture of both deposits on the electron emission portion, the amount of electron emission increases, and an electron source with good uniformity is formed. The voltage application method at this time can be performed similarly by the same connection (see FIG. 13) as in the forming step.
[0108]
After the activation process is completed, it is preferable to perform the stabilization process as in the case of the individual elements. After the envelope 88 is heated and maintained at 80 ° C. or higher, it is exhausted through an exhaust pipe 132 by an exhaust device 135 that does not use oil, such as an ion pump or a sorption pump, so that the atmosphere is sufficiently low in organic substances. The exhaust pipe 132 is sealed. In order to maintain the degree of vacuum after the envelope 88 is sealed, a getter process may be performed. This heats a getter (not shown) disposed at a predetermined position in the envelope 88 by heating using resistance heating or high-frequency heating immediately before or after sealing the envelope 88. And a process for forming a deposited film. The getter usually has Ba or the like as a main component, and maintains the atmosphere in the envelope 88 by the adsorption action of the deposited film.
[0109]
Next, a configuration example of a driving circuit for performing television display based on NTSC television signals on a display panel configured using an electron source with a simple matrix arrangement will be described with reference to FIG. In FIG. 9, 101 is an image display panel, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a synchronizing signal separation circuit, 107 is a modulation signal generator, V_x And V_a Is a DC voltage source.
[0110]
The display panel 101 has a terminal D_ox1 To D_oxm , Terminal D_oy1 To D_oyn And an external electric circuit through a high voltage terminal 87. Terminal D_ox1 To D_oxm A scanning signal for sequentially driving one row (n elements) of an electron source provided in the display panel 101, that is, a group of electron emitting elements arranged in a matrix of m rows and n columns, is applied. Is done.
[0111]
Terminal D_oy1 To D_oyn Is applied with a modulation signal for controlling the output electron beam of each element of one row of electron-emitting devices selected by the scanning signal. The high voltage terminal 87 has a DC voltage source V_a For example, a DC voltage of 10 kV is supplied, which is an accelerating voltage for applying energy sufficient to excite the phosphor to the electron beam emitted from the electron-emitting device.
[0112]
The scanning circuit 102 will be described. The circuit includes m switching elements (in the figure, S₁ Thru S_m It is schematically shown in FIG. Each switching element is a DC voltage power supply V_x Output voltage or 0 [V] (ground level), and the terminal D of the display panel 101 is selected._ox1 To D_oxm And electrically connected. Each switching element S₁ Thru S_m Is a control signal T output from the control circuit 103._scanFor example, it can be configured by combining switching elements such as FETs.
[0113]
DC voltage source V_x In this example, based on the characteristics (electron emission threshold voltage) of the electron-emitting device, a constant voltage is set so that the drive voltage applied to the non-scanned device is equal to or lower than the electron-emitting threshold voltage. Has been.
[0114]
The control circuit 103 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. The control circuit 103 receives the synchronization signal T sent from the synchronization signal separation circuit 106._syncT for each part based on_scan, T_sft And T_mry Each control signal is generated.
[0115]
The synchronization signal separation circuit 106 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside, and can be configured using a general frequency separation (filter) circuit or the like. . The synchronization signal separated by the synchronization signal separation circuit 106 is composed of a vertical synchronization signal and a horizontal synchronization signal._syncIllustrated as a signal. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is input to the shift register 104.
[0116]
The shift register 104 is used for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and a control signal T sent from the control circuit 103._sft (Ie, the control signal T_sft May be rephrased as a shift clock of the shift register 104. ). Data for one line of the serial / parallel converted image (corresponding to drive data for n electron-emitting devices) is I_d1Thru I_dnAre output from the shift register 104 as n parallel signals.
[0117]
The line memory 105 is a storage device for storing data for one line of an image for a necessary time, and a control signal T sent from the control circuit 103._mry According to I_d1Thru I_dnMemorize the contents of The stored content is I_d'1 Thru I_d'n And is input to the modulation signal generator 107.
[0118]
The modulation signal generator 107 is connected to the image data I_d'1 Thru I_d'n The signal source for appropriately driving and modulating each of the electron-emitting devices in response to each of the output signals of the terminal D_oy1 To D_oyn And applied to the electron-emitting devices in the display panel 101.
[0119]
As described above, the electron-emitting device to which the present invention is applicable is an emission current I._e Has the following basic characteristics. That is, there is a clear threshold voltage V for electron emission._thThere is V_thElectron emission occurs only when the above voltage is applied. For voltages above the electron emission threshold, the emission current also changes according to changes in the voltage applied to the device. For this reason, when a pulse voltage is applied to this element, for example, electron emission does not occur even when a voltage lower than the electron emission threshold voltage is applied, but when a voltage higher than the electron emission threshold voltage is applied, A beam is output. At that time, pulse peak value V_m It is possible to control the intensity of the output electron beam by changing. Also, the pulse width P_w It is possible to control the total amount of charges of the output electron beam by changing.
[0120]
Accordingly, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method for modulating the electron-emitting device according to the input signal. When implementing the voltage modulation method, the modulation signal generator 107 generates a voltage pulse of a certain length and can appropriately modulate the peak value of the voltage pulse according to the input data. Can be used. When implementing the pulse width modulation method, the modulation signal generator 107 generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to the input data. A circuit can be used.
[0121]
The shift register 104 and the line memory 105 can be either a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.
[0122]
When the digital signal system is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 106 into a digital signal. For this purpose, an A / D converter may be provided at the output portion of the synchronization signal separation circuit 106. . In this connection, the circuit used in the modulation signal generator 107 is slightly different depending on whether the output signal of the line memory 105 is a digital signal or an analog signal. That is, in the case of a voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 107, and an amplifier circuit or the like is added as necessary. In the case of the pulse width modulation system, the modulation signal generator 107 includes, for example, a high-speed oscillator and a counter that counts the wave number output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. A circuit combining (comparators) is used. If necessary, an amplifier for amplifying the pulse width-modulated modulation signal output from the comparator to the driving voltage of the electron-emitting device can be added.
[0123]
In the case of a voltage modulation method using an analog signal, for example, an amplification circuit using an operational amplifier or the like can be adopted as the modulation signal generator 107, and a level shift circuit or the like can 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 amplifying the voltage up to the driving voltage of the electron-emitting device can be added if necessary.
[0124]
In the image forming apparatus of the present invention that can take such a configuration, each electron-emitting device has a container external terminal D._ox1 To D_oxm , D_oy1 To D_oyn When a voltage is applied via, electron emission occurs. A high voltage is applied to the metal back 85 or the transparent electrode (not shown) via the high voltage terminal 87 to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84, light emission is generated, and an image is formed.
[0125]
The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. Although the NTSC system has been cited as the input signal, the input signal is not limited to this, and in addition to the PAL, SECAM system, etc., the TV signal (for example, the MUSE system, etc.) composed of a larger number of scanning lines than these. High-definition TV) can also be adopted.
[0126]
Next, the above-described ladder-type electron source and image forming apparatus will be described with reference to FIGS.
[0127]
FIG. 10 is a schematic diagram illustrating an example of an electron source having a ladder arrangement. In FIG. 10, 110 is an electron source substrate, and 111 is an electron-emitting device. Reference numeral 112 denotes a common wiring D for connecting the electron-emitting device 111._x1~ D_x10 These are drawn out as external terminals. A plurality of electron-emitting devices 111 are arranged in parallel in the X direction on the substrate 110 (this is called an element row). A plurality of element rows are arranged to constitute an electron source. By applying a driving voltage between the common lines of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to an element row where an electron beam is to be emitted, and a voltage equal to or lower than an electron emission threshold is applied to an element row where no electron beam is desired to be emitted. Common wiring D located between each element row_x2~ D_x9For example, D_x2And D_x3, D_x4And D_x5, D_x6And D_x7, D_x8And D_x9Can be integrated into the same wiring.
[0128]
FIG. 11 is a schematic diagram illustrating an example of a panel structure in an image forming apparatus including a ladder-type arrangement of electron sources. 120 is a grid electrode, 121 is an opening through which electrons pass, D_ox1 To D_oxm Is the container outer terminal, G₁ Thru G_n Is a container external terminal connected to the grid electrode 120. Reference numeral 110 denotes an electron source substrate in which common wiring between element rows is the same wiring. 11, the same parts as those shown in FIGS. 7 and 10 are denoted by the same reference numerals as those shown in these drawings. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 7 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.
[0129]
In FIG. 11, a grid electrode 120 is provided between the substrate 110 and the face plate 86. The grid electrode 120 is for modulating the electron beam emitted from the electron-emitting device 111, and passes the electron beam through a striped electrode provided orthogonal to the element row of the ladder type arrangement. One circular opening 121 is provided for each element. The shape and arrangement position of the grid electrode are not limited to those shown in FIG. For example, a large number of passage openings can be provided as mesh openings, and grid electrodes can be provided around or in the vicinity of the electron-emitting devices.
[0130]
Container outer terminal D_ox1 To D_oxm And grid container outer terminal G₁ Thru G_n Are electrically connected to a control circuit (not shown).
[0131]
In the image forming apparatus of this example, a modulation signal for one image line is simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one by one. Thereby, irradiation of each electron beam to the phosphor can be controlled, and an image can be displayed line by line.
[0132]
The image forming apparatus of the present invention described above can be used as an image forming apparatus as an optical printer configured using a photosensitive drum or the like, in addition to a display device for a television broadcast, a video conference system, a computer, or the like. Can be used.
[0133]
The manufacturing method of the present invention is not necessarily applied only to an image forming apparatus having an envelope, but can also be applied as a manufacturing method of an electron source substrate. For example, by covering a plurality of surface conduction electron-emitting devices as described above with a separable hood on an arrayed substrate, a space temporarily cut off from the outside air is created on the substrate. Activation gas can be introduced and convection can be performed. Thereafter, the hood and the substrate can be separated to produce an electron source substrate.
[0134]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0135]
Example 1
In this embodiment, an image forming apparatus used for display or the like will be described. FIG. 7 is a basic configuration diagram of the image forming apparatus, and FIG. 8 is a fluorescent film. A plan view of a part of the electron source substrate 71 is shown in FIG. FIG. 19 is a cross-sectional view taken along the line A-A ′ in FIG. However, what was shown with the same code | symbol in FIG. 18, FIG. 19 shows the same thing. Here, 71 is an electron source substrate, 72 is D in FIG._xmX-direction wiring (also referred to as lower wiring) corresponding to, 73 is D in FIG._yn4 is a conductive film including an electron emission portion, 2 and 3 are device electrodes, 151 is an interlayer insulating layer, and 152 is an electrical connection between the device electrode 2 and the lower wire 72. This is a contact hole for connection.
[0136]
In the electron source of this embodiment, 300 electron emitting elements are formed on the X direction wiring and 100 electron emitting elements on the Y direction wiring.
[0137]
Next, the manufacturing method will be specifically described according to the order of steps with reference to FIGS.
[0138]
Step-a
After sequentially depositing 5 nm of Cr and 600 nm of Au by vacuum deposition on a substrate 71 on which a 0.5 μm thick silicon oxide film is formed by sputtering on a cleaned blue plate glass, a photoresist (AZ1370) is formed. After spin coating and baking with a spinner, the photomask image is exposed and developed to form a resist pattern for the lower wiring 72, and the Au / Cr deposited film is wet etched to form the lower wiring in a desired shape. 72 is formed.
[0139]
Step-b
Next, an interlayer insulating layer 151 made of a silicon oxide film having a thickness of 1.0 μm is deposited by RF sputtering.
[0140]
Step-c
A photoresist pattern for forming the contact hole 152 is formed in the silicon oxide film deposited in the step b, and the interlayer insulating layer 151 is etched using this as a mask to form the contact hole 152. Etching is CF_Four And H₂ It was based on the RIE (Reactive Ion Etching) method using gas.
[0141]
Step-d
Thereafter, a photoresist (RD-2000N-41 manufactured by Hitachi Chemical Co., Ltd.) is formed as a pattern to be the gap L between the device electrode 2 and the device electrode 3, and Ti of 5 nm thickness and Ni of 100 nm thickness are formed by vacuum deposition. Deposited sequentially. The photoresist pattern was dissolved with an organic solvent, and the Ni / Ti deposited film was lifted off. Element electrodes 2 and 3 having an element electrode interval L of 5 μm and an element electrode width W of 300 μm were formed.
[0142]
Step-e
After forming a photoresist pattern of the upper wiring 73 on the device electrode 3, 5 nm thick Ti and 500 nm Au are sequentially deposited by vacuum deposition, and unnecessary portions are removed by lift-off to obtain a desired shape. An upper wiring 73 was formed.
[0143]
Step-f
A Cr film having a thickness of 100 nm was deposited and patterned by vacuum deposition, and organic Pd (ccp4230, manufactured by Okuno Seiyaku Co., Ltd.) was spin-coated with a spinner, followed by a heat baking treatment at 300 ° C. for 10 minutes. The conductive film 4 made of fine particles of PdO as the main element thus formed has a thickness of 10 nm and a sheet resistance value of 5 × 10.^Four It was Ω / □. Thereafter, the Cr film and the fired conductive film 4 were etched with an acid etchant to form a desired pattern.
[0144]
Process-g
A pattern for applying a resist was formed on portions other than the contact hole 152, and Ti having a thickness of 5 nm and Au having a thickness of 500 nm were sequentially deposited by vacuum evaporation. The contact hole 152 was filled by removing unnecessary portions by lift-off.
[0145]
Through the above steps, the lower wiring 72, the interlayer insulating layer 151, the upper wiring 73, the device electrodes 2 and 3, the conductive film 4 and the like were formed on the substrate 71. Next, an example in which a display device is configured using the electron source created as described above will be described with reference to FIGS.
[0146]
After fixing the substrate 71 on which a large number of planar surface conduction electron-emitting devices are produced as described above on the rear plate 81, the face plate 86 (the fluorescent film 84 on the inner surface of the glass substrate 83, and 5 mm above the substrate 71). The metal back 85 is formed through a support frame 82, and frit glass is applied to the joint of the face plate 86, the support frame 82, and the rear plate 81, and at 410 ° C. for 10 minutes or more in the atmosphere. The envelope 88 was produced by sealing by firing (see FIG. 7). The substrate 71 was fixed to the rear plate 81 with frit glass. In FIG. 7, 74 is an electron-emitting device, and 72 and 73 are wirings in the X direction and Y direction, respectively.
[0147]
As the fluorescent film 84, a black fluorescent color fluorescent film composed of a black conductive material 91 and a phosphor 92 was used (see FIG. 8A). Specifically, a black stripe was formed first, and each color phosphor was applied to the gap portion to produce a fluorescent film 84. A slurry method was used as a method of applying the phosphor on the glass substrate 83. A metal back 85 was provided on the inner surface side of the fluorescent film 84. The metal back 85 was manufactured by performing a smoothing process (usually called “filming”) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then vacuum-depositing Al. When performing the above-described sealing, in the case of a color, each color phosphor must correspond to the electron-emitting device, so that sufficient alignment was performed.
[0148]
The envelope 88 completed as described above was connected to a vacuum apparatus evacuated by a magnetic levitation turbomolecular pump through an exhaust pipe (not shown). Then, the inside of the envelope 88 is 1.3 × 10^-FourExhaust to Pa.
[0149]
Container outer terminal D_x1Or D_xm(M = 300) and D_y1Or D_ynA voltage was applied between the device electrodes 2 and 3 of the electron-emitting device 74 through (n = 100), and the electron-emitting portion 5 was created by energizing the conductive film 4 (forming process).
[0150]
The voltage waveform of the forming process is shown in FIG. In FIG. 3B, T₁ And T₂ Is the pulse width and pulse interval of the voltage waveform.₁ 1 msec. , T₂ 10 msec. The peak value of the rectangular wave (peak voltage at the time of forming) was boosted at a step of 0.1 V, and the forming process was performed. Further, during the forming process, at the same time, a voltage of 0.1 V and T₂ A resistance measurement pulse was inserted between them to measure the resistance. The forming process was ended when the measured value with the resistance measurement pulse became about 1 MΩ or more, and at the same time, the voltage application to the element was ended. The forming voltage VF of each element was 5.0V.
[0151]
The electron emission portion 5 thus prepared was in a state where fine particles mainly composed of palladium were dispersed and the average particle size of the fine particles was 3 nm.
[0152]
Next, 1.01 Pa of acetylene gas diluted with 1% nitrogen is introduced into the envelope 88 via a vacuum apparatus, and then nitrogen gas is introduced, and the pressure in the envelope is set to 1.01 × 10 6.^Five The valve connecting the exhaust pipe and the vacuum device was closed.
[0153]
Container outer terminal D_x1Or D_xm(M = 300) and D_y1Or D_ynA voltage was applied between the device electrodes 2 and 3 of the electron-emitting device 74 through (n = 100) to perform an activation process.
[0154]
The voltage application conditions in the activation process are as follows: the peak value is ± 10 V, and the pulse width is 0.1 msec. , Pulse interval 5 msec. The rectangular wave of FIG. 4 (FIG. 4B) was used. Thereafter, the peak value of the rectangular wave is 3.3 mV / sec. The voltage was gradually increased at, and the voltage application was terminated when the voltage reached ± 14V.
[0155]
Further, when performing the activation process, as shown in FIG. 14A, the rear plate 81 of the envelope 88 is heated linearly in the direction along the upper wiring and outside the electron source substrate 71. (The heating temperature was about 60 ° C.). Then, the valve | bulb which connects an exhaust pipe and a vacuum device was opened, and the activated gas in the envelope 88 was exhausted.
[0156]
Finally, as a stabilization process, about 1.33 × 10^-FourAfter baking at 150 ° C. for 10 hours at a pressure of Pa, the exhaust pipe (not shown) was welded by heating with a gas burner, and the envelope 88 was sealed.
[0157]
In the image forming apparatus of the present invention completed as described above, each electron-emitting device has a container external terminal D._x1Or D_xm(M = 300) and D_y1Or D_ynThrough (n = 100), a scanning signal and a modulation signal are respectively applied from a signal generating means (not shown) to emit electrons, and a high voltage of 6 kV or more is applied to the metal back 85 through the high voltage terminal 87, and the electron beam Was accelerated, collided with the fluorescent film 84, and excited and emitted to display an image.
[0158]
The luminance distribution of the display image was measured with a luminance meter. Here, the luminance distribution of the display image is obtained by dividing the display image area into 5 × 5 areas and about 1 cm at the center.² The luminance was measured at 25 locations having the following areas, and the luminance distribution was defined as follows.
[0159]
Luminance distribution (%) = (Standard deviation of luminance / Average luminance) × 100
As a result, the luminance distribution of the image forming apparatus of this example was 5%.
[0160]
<< Comparative Example 1 >>
In Example 1, when performing the activation process, it was performed in the same manner except that the linear heating of the rear plate 81 of the envelope 88 was not performed. The luminance distribution of the display image was measured in the same manner as in Example 1 and found to be 10%.
[0161]
Example 2
A ladder-type electron source substrate having a configuration similar to that of FIG. 10 and having a large number of electron-emitting devices 111 between two adjacent wirings was produced. Here, 120 electron-emitting devices were formed between adjacent wirings on the electron source substrate 110, and 40 such adjacent wiring sets were created.
[0162]
The electron source substrate was prepared in the same manner as steps df shown in Example 1 on a substrate in which a silicon oxide film having a thickness of 500 nm was formed on a cleaned soda glass by a sputtering method.
[0163]
Next, after fixing the electron source substrate 110 on the rear plate 81, the grid electrode 120 having the electron passage holes l21 is disposed above the electron source substrate 110 in a direction orthogonal to the wiring electrode 112 of the electron-emitting device. . Further, a face plate 86 prepared in the same manner as in the first embodiment is arranged 5 mm above the electron source substrate 110 via the support frame 82, and frit glass is applied to the joint portion of the face plate 86, the support frame 82, and the rear plate 81. And it sealed by baking for 10 minutes or more at 410 degreeC in air | atmosphere, and created the envelope 88 (refer FIG. 11). The electron source substrate 110 was fixed to the rear plate 81 with frit glass.
[0164]
When performing the above-described sealing, in the case of a color, each color phosphor must correspond to the electron-emitting device, so that sufficient alignment was performed.
[0165]
Further, inside the envelope 88, as shown in FIG. 17, a moisture removing body 181 in which calcium chloride particles are placed in a stainless mesh container is placed in the vicinity of the electron source substrate 71. The moisture removing body 181 was fixed with a partition frame 182 so as not to move inside the envelope. The stainless mesh container has a mesh roughness of # 300 so that calcium chloride particles do not come out and are in sufficient contact with the atmosphere inside the envelope.
[0166]
The envelope 88 completed as described above was connected through an exhaust pipe (not shown) to a vacuum apparatus that can be exhausted by a vacuum pump that does not use oil. Then, inside the envelope 88 is 1.33 × 10^-FourExhaust to Pa.
[0167]
Container outer terminal D_x1Or D_xmA voltage was applied between the device electrodes of the electron-emitting device 111 through (m = 80), and the electron-emitting portion 5 was created by conducting a conductive process (forming process) on the conductive film 4.
[0168]
Next, 1.01 Pa of acetylene gas diluted with 1% nitrogen is introduced into the envelope 88 via a vacuum apparatus, and then nitrogen gas is introduced, and the pressure in the envelope 88 is set to 1.01 ×. 10^Five Up to Pa, the valve connecting the exhaust pipe and the vacuum device was closed.
[0169]
Container outer terminal D_x1Or D_xmA voltage was applied between the device electrodes of the electron-emitting device 111 through (m = 80) to perform the activation process.
[0170]
The voltage application conditions in the activation process are as follows: the peak value is ± 10 V, and the pulse width is 0.1 msec. , Pulse interval 5 msec. The rectangular wave of FIG. 4 (FIG. 4B) was used. Thereafter, the peak value of the rectangular wave is 3.3 mV / sec. The voltage was gradually increased at, and the voltage application was terminated when the voltage reached ± 14V.
[0171]
In addition, when performing the activation process, as shown in FIG. 17, heating was performed by a linear heater 161 at a location facing the position of the moisture removing body 181 on the rear plate 81 of the envelope 88 (heating temperature is About 60 ° C.).
[0172]
Then, the valve | bulb which connects an exhaust pipe and a vacuum device was opened, and the activated gas in the envelope 88 was exhausted.
[0173]
Finally, as a stabilization process, about 1.33 × 10^-FourAfter baking at 150 ° C. for 10 hours at a pressure of Pa, the same voltage application as in Example 1 was performed, and the exhaust pipe (not shown) was welded by heating with a gas burner to seal the envelope 88. went.
[0174]
In the image forming apparatus of the present invention completed as described above, each electron-emitting device has a container external terminal D._x1Or D_xmElectrons are emitted by applying a voltage through (m = 80), and the emitted electrons pass through the electron passage hole l21 of the grid electrode 120, and then through a high voltage terminal 87, a metal back or a transparent electrode (not shown). Is accelerated by a high pressure of several kV or more applied to, and collides with the fluorescent film 84 to excite and emit light. At that time, a voltage corresponding to the information signal is applied to the grid electrode 120 as a container external terminal G.₁ Or G_n By applying through the electron beam, the electron beam passing through the electron passage hole l21 is controlled to display an image.
[0175]
In this embodiment, the insulating layer is SiO.₂ By placing the grid electrode 120 having the electron passage hole 121 having a diameter of 50 μm 10 μm above the electron source substrate 110 (not shown), when an acceleration voltage of 6 kV is applied, the on / off of the electron beam is within 50 V It was possible to control with the modulation voltage. Further, the luminance distribution of the display image was measured in the same manner as in Example 1 and found to be 4%.
[0176]
<< Comparative Example 2 >>
In Example 2, when performing the activation process, it was performed in the same manner except that the linear heating of the rear plate 81 of the envelope 88 was not performed. And when the distribution of the display image was measured similarly to Example 1, it was 15%.
[0177]
In the above embodiment, an image forming apparatus using a matrix arrangement electron source (Example 1) and an image forming apparatus using a ladder arrangement electron source and a grid electrode (Example 2) are shown. The present invention can be applied to any device as long as the electrons from the element collide with the phosphor.
[0178]
【The invention's effect】
As described above, according to the present invention, an electron source having a plurality of electron-emitting devices with uniform electron emission characteristics can be obtained. In an image forming apparatus configured using such an electron source, uneven brightness is obtained. A uniform display image can be obtained. In addition, the electron source obtained by the manufacturing method of the present invention can be applied to an electron beam (EB) drawing apparatus and a recording apparatus. Furthermore, according to the manufacturing method of the present invention, these devices can be produced by a simple process.
[Brief description of the drawings]
1A and 1B are a schematic plan view and a cross-sectional view showing an example of the configuration of a basic surface conduction electron-emitting device according to the present invention.
2 is a process diagram showing an example of a method for manufacturing the surface conduction electron-emitting device of FIG. 1. FIG.
FIG. 3 is a diagram illustrating an example of a voltage waveform of energization forming according to the present invention.
FIG. 4 is a diagram showing an example of a voltage waveform in an activation process according to the present invention.
FIG. 5 shows an emission current I for a surface conduction electron-emitting device according to the present invention._e And element current I_f And element voltage V_f It is a figure which shows an example of the relationship.
FIG. 6 is a schematic diagram showing an example of an electron source arranged in a simple matrix according to the present invention.
FIG. 7 is a schematic view showing an example of a display panel of the image forming apparatus of the present invention.
FIG. 8 is a schematic diagram showing an example of a fluorescent film.
FIG. 9 is a block diagram illustrating an example of a drive circuit for performing display on the image forming apparatus in accordance with an NTSC television signal.
FIG. 10 is a schematic diagram showing an example of a ladder-type electron source according to 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 vacuum exhaust apparatus for performing a forming process and an activation process according to the present invention.
FIG. 13 is a schematic diagram showing an example of a connection method for a forming process and an activation process according to the present invention.
FIG. 14 is a schematic view showing an example of a convection method for an activated gas using a temperature difference according to the present invention.
FIG. 15 is a schematic view showing an example of a convection method for an activated gas using an electric field according to the present invention.
FIG. 16 is a schematic diagram showing an example of a convection method of an activated gas using a magnetic field according to the present invention.
FIG. 17 is a schematic view showing an example in which an activation inhibitor removing means is provided in the convection path of the activation gas according to the present invention.
18 is a plan view of electron sources of Example 1 and Comparative Example 1. FIG.
19 is a cross-sectional view of electron sources of Example 1 and Comparative Example 1. FIG.
20 is a manufacturing diagram of electron sources of Example 1 and Comparative Example 1. FIG.
FIG. 21 is a manufacturing diagram of electron sources of Example 1 and Comparative Example 1;
[Explanation of symbols]
1 Substrate
2, 3 element electrodes
4 Conductive film
5 Electron emission part
71 Electron source substrate
72 X direction wiring
73 Y-direction wiring
74 Electron emitter
75 connection
81 Rear plate
82 Support frame
83 Glass substrate
84 Fluorescent membrane
85 metal back
86 Face plate
87 High voltage terminal
88 Envelope
91 Black conductive material
92 Phosphor
101 Display panel
102 Scanning circuit
103 Control circuit
104 Shift register
105 line memory
106 Sync signal separation circuit
107 Modulation signal generator
V_x , V_a   DC voltage source
110 Electron source substrate
111 electron-emitting devices
112 Common wiring for wiring electron-emitting devices
120 grid electrode
121 Opening for electrons to pass through
130 Valve
131 Image display device
132 Exhaust pipe
133 Vacuum chamber
134 Gate valve
135 Exhaust system
136 Pressure gauge
137 Quadrupole mass spectrometer
138 Gas introduction line
139 Gas introduction amount control device
140 Sources of substances introduced
141 Common electrode
142 Power supply
143 Resistance for current measurement
144 Oscilloscope
151 Interlayer insulation layer
152 contact hole
161 Heater
162 ions
163,164 Counter electrode (discharge electrode)
165,166 Counter electrode
167 High frequency power supply
168 DC power supply
169 coil
170-173 Counter electrode (discharge electrode)
174 High frequency power supply
175,176 ions
181 Moisture remover
182 Partition frame

Claims (7)

In a method of manufacturing an electron source comprising a plurality of electron-emitting devices having a conductive film including an electron-emitting portion between a pair of device electrodes in an envelope having an internal space,
A gas containing at least an organic substance and an inert gas is sealed inside the envelope so as to have a pressure in the viscous flow region, and then a voltage is applied between the device electrodes to at least carbon or / And an activation process for depositing a carbon compound, wherein a gas containing the organic substance and an inert gas is convected inside the envelope. In an electron source manufacturing method comprising a plurality of electron-emitting devices having a conductive film including an electron-emitting portion between a pair of device electrodes on a substrate,
An envelope that temporarily forms a space cut off from the outside air is provided on the substrate on which the conductive film including the device electrode and the electron emission portion is formed, and at least an organic substance and an inert material are provided in the space. An energization step of depositing carbon or / and a carbon compound on at least the electron emission portion by applying a voltage between the device electrodes after sealing the gas containing the gas so as to have a pressure in the viscous flow region; A method for producing an electron source, comprising convection of a gas containing the organic substance and an inert gas in the space. 3. The method of manufacturing an electron source according to claim 1, wherein a gas including the organic substance and an inert gas in the envelope is convected by giving a temperature distribution to the envelope. The gas containing the organic substance is convected by generating ions in the gas containing the organic substance and the inert gas inside the envelope and applying an electromagnetic force to the ions. Or the manufacturing method of the electron source of 2. 5. The method of manufacturing an electron source according to claim 1, wherein the total pressure of the gas containing the organic substance and the inert gas inside the envelope is 100 Pa or more. The electron-emitting device, method of manufacturing an electron source according to any one of claims 1 to 5, characterized in that a surface conduction electron-emitting device. An electron source comprising a plurality of electron-emitting devices having a conductive film including an electron-emitting portion between a pair of device electrodes in an envelope having an internal space, and an image by irradiation of an electron beam emitted from the electron source in the manufacturing method of an image forming apparatus comprising an image forming member for forming a manufacturing method of an image forming apparatus, characterized by producing by the method according to the electron source in any of claims 1-6.

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