JP2000251778A - Display panel and panel sealing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display panel having high reliability, capable of keeping high vacuum inside an airtight container. SOLUTION: In this display panel composed of an airtight container a part of which is composed by sealing a rear plate 1 where a draw out line of a thick film (thick film wiring 2) made of metal particles is formed, and a support frame 5 for supporting the rear plate 1, the thick film wiring 2 is drawn out from the inside of the airtight container to the outside of the container, and at least the interval between the draw out line and the support frame 5 is sealed by insulating layers 3, 4. The insulating layer 4 seals the rear plate 1 and the support frame 5, and the insulating layer 3 made of material which can be impregnated into the thick film wiring 2 is formed so as to cover a sealing part of the thick film wiring 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel having an airtight structure. Further, the present invention relates to a panel sealing method performed in such a display panel.

[0002]

2. Description of the Related Art As one of high vacuum panels using thick film wiring, there is a surface electron emission type panel. In addition, PD
There are P, FED, etc., but here, a surface electron emission type panel which requires a particularly high degree of vacuum will be described below as a typical example.

As an example of a surface conduction electron-emitting device, M.
I. Elinson, RadioFng. ElectronPhys, 10.1290 (1965). Surface conduction electron-emitting devices are
Electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel with the film surface. As such a surface conduction electron-emitting device, the above-mentioned Sinson et al.
those using n0 ₂ thin film, by an Au thin film (G.Dittm
er, Thin Solid Films, 9, 317 (1972)), In 2 0 3 / S
n0 ₂ by thin film (M.Hartwell and CGFonstad, I
EEE Trans. ED Conf., 519 (1975)), a method using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported. As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.E. FIG. 9 schematically shows a device configuration of the Hartwell.

In FIG. 9, a conductive thin film 102 made of a metal oxide thin film is formed on a substrate 101 by sputtering in an H-shaped pattern, and the conductive thin film 102 emits electrons by an energization process called energization forming described later. Part 1
03 is formed. In FIG. 9, the element electrode interval L is set to 0.5 to 1 mm, and W is set to 0.1 mm.

In the above surface conduction electron-emitting device,
In general, before the electron emission, the conductive thin film 102 is formed in advance by an energization forming process to form the electron emission portion 103. Here, the energization forming is to apply a DC voltage or a very gentle rising voltage to both ends of the conductive thin film 102 and to apply a current to locally destroy, deform or alter the conductive thin film 102, and to obtain an electrically high-resistance state. Electron emission part 1
03 is formed. In the electron emitting section 10, a crack is generated in a part of the conductive thin film 102, and electrons are emitted from the vicinity of the crack.

[0006] In the surface conduction type electron-emitting device subjected to the energization forming process, a voltage is applied to the conductive thin film 102 and a current flows through the device, so that the electron-emitting portion 103 is formed.
The electrons are emitted from.

Japanese Patent Application Laid-Open No. 9-27758 discloses an example of a display panel having the above-described surface conduction electron-emitting device.
No. 6, in consideration of the reliability of the vacuum sealing portion, FIG.
As shown in FIG. 7, there is a pattern in which the pattern of the lead wire 202 is folded back by the vacuum sealing portion 201. According to this structure, the occurrence of a vacuum leak due to a wiring step under the support frame caused by an increase in the thickness of the lead wire is reduced.

[0008]

In the case of a layer display panel using the above-described surface conduction electron-emitting device, the pattern of the lead line of the vacuum sealing portion is formed as shown in FIG. However, the following leak problem occurs.

In the case where a thick film wiring using, for example, Ag paste as the lead wire, the bonding state of the Ag particles cannot be completely melted at a low temperature, and a gap is formed between the metal particles. A minute path is formed by such a gap between the metal particles, and a leak occurs through this path, so that a high vacuum cannot be maintained.

The problem of the gap between the metal particles can be solved by sufficiently firing at a temperature higher than the softening point of the metal particles in the thermal firing step. However, since the firing temperature is restricted as described below, It is not easy to increase the firing temperature.

Although it depends on the profile of the firing temperature, when firing a blue plate substrate, it is necessary to fire at 515 ° C. or lower to cause deformation. Furthermore, when precision is required, it is necessary to fire at 495 ° C. or lower. If these conditions are not satisfied, the blue plate substrate will be deformed, and the pitch and long dimension of the pattern or the like will be out of order before firing. In order to prevent this problem of deformation, low-temperature firing has been required.

The wiring formed by the above-described low-temperature firing has a vacuum degree.
10^-6Experience shows that there is no problem up to torr
You. However, if a higher vacuum is required, for example,
10 ^-8torr could not be achieved. This cause
Means that the metal particles were heated near the softening point as described above.
In this case, the bonding between particles does not progress very much, and fine voids are created.
It is thought to be. In particular, metal particles (eg, A
g) In order to prevent projections due to aggregation,
If the cloth is made uniform, the temperature at which the metal particles
If formed at a temperature lower than
Leakage rate is large and reliability is problematic
Had occurred.

An object of the present invention is to solve the above-mentioned leak problem and to provide a highly reliable display panel in which the inside of the panel is maintained in a high vacuum and reduced pressure atmosphere. Another object is to provide a panel sealing method for realizing such a highly airtight display panel.

[0014]

In order to achieve the above object, a display panel according to the present invention is characterized in that at least a part of an airtight container constituting the panel is provided with a plate on which a thick film lead line made of metal particles is formed. In a display panel in which a support frame for supporting the display panel is sealed, the lead line is drawn out of the airtight container to the outside of the container, and at least a first and a first line between the lead line portion and the support frame. It is characterized by being sealed by a second insulating layer.

In the above case, the first insulating layer is configured to seal the plate and the support frame, and the second insulating layer is provided in contact with the first insulating layer; You may comprise so that the sealing part of the said lead wire may be covered.

In the above case, the second insulating layer may be made of a material that can be impregnated into the lead wire.

Further, the second insulating layer may be provided so as to overlap the first insulating layer, and may be provided so as to extend from the first insulating layer to the inside of the container, to the outside of the container, or to both sides.

Further, a row-direction wiring and a column-direction wiring are provided on the plate, and an interlayer insulating layer provided at a portion where the row-direction wiring and the column-direction wiring overlap with each other.
May be the same material.

The panel sealing method of the present invention is a panel sealing method in which a support frame supporting the plate is sealed to a plate provided with a thick film lead line made of metal particles to form an airtight structure. Then, the plate and the support frame are sealed with a first insulating layer, and a portion of the lead wire sealed with the first insulating layer is further covered with a second insulating layer. And sealing.

In the above case, a material capable of impregnating the lead wire may be used as the material of the second insulating layer.

(Operation) As described in the above-mentioned problem,
The main cause of the leak is a minute gap between the particles of the metal particle (for example, Ag particles) paste constituting the lead line drawn out from the inside of the airtight container to the outside. In the present invention as described above, the sealing portion is formed of the first and second insulating layers.
Because of the layer structure, one insulating layer can be used for sealing the support frame, and the other insulating layer can be used for preventing leakage from the lead wire.

In the invention in which a material that can be impregnated into the lead wire is used as the material of the insulating layer (second insulating layer) used to prevent leakage from the lead wire, the gap between the metal particles of the lead wire is formed in the gap. The insulating layer is impregnated, thereby filling the path causing the leak.

It should be noted that the second insulating layer does not completely melt,
Even if the lower portion of the lead wire is not sufficiently impregnated, the gap between the metal particles of the lead wire is impregnated with the second insulating layer in the vicinity of the interface between the second insulating layer and the lead wire. There is no. This second insulating layer comprises a first insulating layer.
Is provided so as to cover a portion where the sealing portion of the support frame using the insulating layer and the lead line are in contact with each other, so that a path due to a gap between the metal particles near the support frame sealing portion is not formed. . Therefore, the length of the path causing the leak becomes longer, and the leak is reduced accordingly. In particular, if you have a structure that holds the vacuum with vacuum auxiliary equipment such as a vacuum getter, the path that could not be filled,
Since it is much smaller than the particle size of the metal (usually 0.1 to 2.0 μm), the amount of reduction in the degree of vacuum due to leakage is small, considering that the diffusion time of gases such as oxygen and carbon dioxide is extremely long.

[0024]

Next, embodiments of the present invention will be described with reference to the drawings.

First, the overall configuration of a display panel to which the present invention is applied will be described.

FIG. 2 is a perspective view showing an example of a display panel portion constituting a flat type image display device, in which a part of the panel is cut away to show the internal structure. In the figure, 31
15 is a rear plate, 3116 is a support frame (side wall), 31
Reference numeral 17 denotes a face plate, and a rear plate 311
5. The support frame 3116 and the fuse plate 3117 are bonded and sealed using frit glass or the like to form an envelope (airtight container) for maintaining the inside of the display panel at a vacuum.

A substrate 3111 is fixed to the rear plate 3115. On this substrate 3111, N × M cold cathode elements 3112 are formed in a matrix. Here, N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels.

The N × M cold cathode elements 3112
Indicates that the M row direction wirings 3113 and N
It is wired by the column direction wiring 3114. These substrate 3111, cold cathode element 3112, row direction wiring 311
The portion constituted by 3 and the column direction wiring 3114 is called a multi-electron beam source. In addition, the row direction wiring 3113
And at least a portion where the column wiring 3114 intersects
An insulating layer (not shown) is formed between both wirings, and electrical insulation is maintained.

On the lower surface of the face plate 3117, a phosphor film 3118 made of a phosphor is formed, and phosphors (not shown) of three primary colors of red (R), green (G), and blue (B) are applied. Divided. A black body (not shown) is provided between the phosphors of the respective colors constituting the fluorescent film 3118, and a metal back 3119 made of Al or the like is formed on the surface of the fluorescent film 3118 on the rear plate 3115 side. ing.

Row direction terminal 3113a, column direction terminal 311
Reference numeral 4a denotes an electric connection terminal provided for electrically connecting the display panel to an electric circuit (not shown). The sealing at this portion has an airtight structure which is a feature of the present invention described later. The row direction terminal 3113a is electrically connected to the row direction wiring 3113 of the multi electron beam source, and the column direction terminal 3114a is electrically connected to the column direction wiring 3114 of the multi electron beam source.

The inside of the hermetic container is maintained at a vacuum of about 10 ⁻⁶ Torr. The structural support (called a spacer or a rib) 3120 is for preventing deformation or destruction of the rear plate 3115 and the face plate 3117 due to a pressure difference between the inside and the outside of the airtight container, and is made of a relatively thin glass plate.

In the display panel configured as described above,
The distance between the substrate 3111 on which the multi-beam electron source is formed and the face plate 3116 on which the fluorescent film 3118 is formed is generally kept at a sub-millimeter to several millimeters, and the inside of the hermetic container is kept at a high vacuum as described above.

Next, a feature of the display panel of the present invention is as follows.
An airtight structure of a sealing portion between the rear plate on which the row direction terminals and the column direction terminals are formed and the side wall (support frame) will be described.

FIG. 1 shows an example of a cross-sectional structure of an airtight structure of a sealing portion between a rear plate and a support frame of a display panel according to the present invention. In FIG. 1, the rear plate 1, the thick film wiring 2, and the support frame 5 are respectively the rear plate 311 shown in FIG.
5. Row direction terminal 3113a (or column direction terminal 3114)
a) corresponds to the support frame 3116. In this airtight structure,
Two insulating layers 3 and 4 are formed between the support plate 5 and the rear plate 1 on which the thick film wiring (lead wire) 2 is formed.

Thick film wiring 2 formed on rear plate 1
Is obtained by printing a conductive paste containing a metal material by a screen printing method, and has a thickness of several μm to several tens μm. Here, the description will be made on the assumption that the thick film wiring 2 is formed by printing an Ag paste.

The insulating layer 3 is for improving the airtightness of the thick film wiring 2 and is made of a material that can be impregnated into the thick film wiring 2. Specifically, the material of the insulating layer 3 is a material having characteristics similar to the glass contained in the Ag paste (the Ag paste usually contains several percent of glass in addition to the Ag particles). Alternatively, they are made of the same glass material. On the other hand, the insulating layer 4 is for bonding and fusing the support frame 5, and is made of the same material as the support frame 5, such as low-melting glass (frit glass).

In the above-described hermetic structure, the glass component of the insulating layer 3 is impregnated into the thick-film wiring 2 so that the gaps of Ag particles near the interface of the thick-film wiring 2 are filled. And the inside of the airtight container can be maintained at a high vacuum.

FIG. 3 is a diagram schematically showing the structure of a sealing portion of the entire rear plate of the display panel having the airtight structure shown in FIG. 1 described above. In FIG. 3, a broken line portion faces the rear plate. 2 shows a face plate arranged in a horizontal direction.

Column-directional wiring (lower wiring) and row-directional wiring (upper wiring) are formed in the effective display area 15 on the rear plate 11, and a surface conduction electron-emitting device 16 is formed near each intersection of these wirings. Have been. These upper wiring and lower wiring are the lead wires 12 drawn out of the hermetic container, respectively.
a, 12b. In FIG. 3, the upper wiring and the lower wiring are omitted.

The lead wires 12a and 12b pass through the sealing portion below the support frame 14 and are taken out of the airtight container. At least in this portion, the airtight structure (see FIG. 1) which is a feature of the present invention described above. ). In the example shown in FIG. 3, the insulating layer 13 for improving the airtightness of the lead wires 12a and 12b is formed in a frame shape along a portion where the support frame 14 is sealed. The width of the insulating layer 13 is
May be wider than the width of the portion to be sealed.
In this case, the width of the insulating layer 13 may be widened to the outside of the airtight container with respect to the sealing portion of the support frame 14 as shown in FIG. You may provide so that it may spread. Further, the width of the insulating layer 13 may be widened in both directions inside and outside the airtight container from the portion where the support frame 14 is sealed.

An insulating layer (not shown) is formed on the insulating layer 13 at a portion where the support frame 14 is sealed, and the support frame 14 is adhered and sealed thereto. In the configuration shown in FIG. 3, this insulating layer overlaps with the support frame 14 and is omitted for convenience.

Next, a procedure for manufacturing a display panel having the above-described rear plate sealing portion will be described.

First, a conductive film made of a metal material is printed on the well-washed rear plate 11 to form device electrodes 16. The electrode interval between the pair of device electrodes is several μm to several hundred μm,
The film has a thickness of several hundred to several thousand angstroms and is formed by a printing method. This element electrode may be patterned by photolithography to form a conductive thin film. The thickness of the conductive thin film is preferably in the range of several tens of angstroms to several thousand angstroms, and can be appropriately set.

Then, a conductive paste made of thick metal particles is printed, and the lower wiring pattern (lead lines 12a, 12a) is printed.
2b). These lower wiring patterns are formed so as to be in contact with a part of the device electrode. The thickness of the lower wiring pattern is in the range of several tens μm to several μm.

After the lower wiring pattern is formed,
An insulating paste is printed at a position where an upper wiring to be formed later on the lower wiring intersects and baked to form an insulating layer. This insulating layer is for insulating the lower wiring from the upper wiring, and has a thickness in the range of several tens μm to several μm.

Next, a conductive paste made of thick metal particles is printed and baked on the insulating layer in a direction perpendicular to the lower wiring to form an upper wiring. The upper wiring is insulated from the lower wiring by the insulating layer, but is electrically connected to the element electrodes. The thickness of the upper wiring is in the range of several tens μm to several μm.

As described above, the lead wires 12a, 12a
b, the upper and lower wirings and the device electrodes are formed, and then the lead wires 12a, 12a near the sealing portion of the rear plate 11 are formed.
In addition to forming an insulating layer 13 for improving the airtightness of b, an insulating layer made of low-melting glass (frit glass) or the like is provided on the insulating layer 13, and a support frame 14 is adhered to the insulating layer and heat-sealed. I do. Finally, the face plate is sealed to the support frame 14 to complete the airtight container. The description of the manufacturing procedure of the face plate is omitted.

In the embodiment described above, the face plate, the rear plate, and the support frame are made of quartz glass, glass having a reduced content of impurities such as Na, blue plate glass, and glass obtained by laminating Si02 on blue plate glass by sputtering or the like. Substrates and the like, ceramics such as alumina and the like can be used. Although it is preferable to use soda-lime glass for the plate in consideration of cost, a substrate that can be heated to around 600 ° C., for example, PD200 manufactured by Asahi Glass Co., Ltd. may be used.

As the material for the device electrode, the lower wiring, and the upper wiring, any material may be used as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, P
Printed conductors composed of metals or alloys such as t, Ti, A1, Cu, and Pd, and metals such as Pd, Ag, Au, Ru, and Pd-Ag. In the present invention,
Of these, materials made of metal particles are targeted. Both upper and lower wirings are formed near the softening point. The softening point in this case is
When a blue plate is used, the temperature is preferably about 495 ° C or lower. In addition, since the printing method is inexpensive in terms of material, it is preferable to use a printed Ag paste as the conductive wiring material and a glass-based material as the insulating paste. The insulating paste used for the interlayer insulating layer provided between the upper and lower wirings uses a material in consideration of the wettability with the material of the lower wiring.

The low melting point glass (frit glass) used for bonding the support frame 14 has a melting point of 400
What is generally marketed at 〜550 ° C. can be used.

Next, the basic structure of the surface conduction electron-emitting device provided in the display panel of the present invention having the above-described hermetic structure will be described. FIGS. 4A and 4B are schematic diagrams showing a configuration of a surface conduction electron-emitting device, wherein FIG.
(B) is a sectional view.

In FIG. 4, 21 is a substrate, 22 and 23 are device electrodes, 24 is a conductive electrode, and 25 is an electron emitting portion. As the substrate 21, quartz glass, glass with a reduced impurity content such as Na, blue plate glass, a glass substrate on which Si02 is deposited by a sputtering method or the like, a ceramic substrate such as alumina, or the like can be used.

As the material of the element electrodes 22 and 23 facing each other, general conductivity can be used. Here, a metal or alloy such as Pt or Ti, or a conductor composed of a metal oxide and glass is used. You can choose from: Device electrode interval L, device electrode length W, conductive thin film 2
The shape and the like of 4 are designed in consideration of an applied form and the like. The thickness is preferably in the range of several thousand angstroms to several hundreds of μm, and more preferably in the range of 1 to 200 μm in consideration of the voltage applied between the device electrodes.

The element electrode length W 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.
The film thickness d of the device electrodes 22 and 23 is in the range of 100 Å to 0.2 μm. In addition to the configuration shown in FIG. 4, a configuration in which a conductive thin film 24 and opposing element electrodes 22 and 23 are laminated in this order on a substrate 21 may be adopted.

It is preferable to use a fine particle film made of fine particles for the conductive thin film 24 in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage of the device electrodes 22 and 23, the resistance value between the device electrodes 22 and 23, forming conditions described later, and the like, but is usually in the range of several to several thousand angstroms. It is more preferable that the thickness be in the range of 10 to 500 angstroms. The resistance value of Rs is 1 × 10 ² or more.
The value is 1 × 10 ⁷ Ω. Rs has a thickness t, a width w,
A value that appears when the resistance R of a thin film having a length of 1 is R; Rs (1 / W). When the resistivity of a thin film material is ρ, R
It is represented by s = ρ / t.

Next, the forming process will be described by taking an energizing process as an example. However, the forming process is not limited to this, and any method may be used as long as the film is cracked to form a high resistance state. May be.

The material constituting the conductive thin film 24 was formed by the BJ method using Pd. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles are aggregated, and (Including the case where an island-shaped structure is formed). The particle size of the fine particles is several angstroms to 1
It is in the range of μm, preferably in the range of 10 to 200 Å.

The electron-emitting portion 25 is constituted by a high-resistance crack formed in a part of the conductive thin film 24 and depends on the film thickness, film quality, material, and a method such as energization forming which will be described later. It will be. In some cases, the inside of the electron-emitting portion 25 contains conductive fine particles having a particle diameter of 30 or less of 1000 angstroms. The conductive fine particles contain some or all of the elements of the material constituting the conductive thin film O04. The electron emitting portion 25 and the conductive thin film 24 in the vicinity thereof may contain carbon or a carbon compound.

There are various methods for manufacturing the above-described surface conduction electron-emitting device. One example is schematically shown in FIG. In FIG. 5, the same parts as those shown in FIG. 4 are denoted by the same reference numerals as those in FIG.

First, as shown in FIG.
After washing sufficiently with detergent, pure water and organic solvent, etc., after depositing the element electrode material by vacuum evaporation method, sputtering method, etc.
For example, the device electrodes 22 and 23 are formed on the substrate 21 using a photolithography technique.

Subsequently, as shown in FIG. 5B, an organic metal solution is applied to the substrate 21 provided with the device electrodes 22 and 23 to form an organic metal thin film. As the organometallic solution, a solution of an organometallic compound containing the metal of the material of the conductive thin film 24 as a main element can be used. The organic metal thin film is heated and baked, and patterned by lift-off, etching, or the like to form a conductive thin film 24. Here, the method of applying the organometallic solution has been described.
The method of forming 4 is not limited to this, but includes a vacuum deposition method,
Sputtering, chemical vapor deposition, dispersion coating, dipping, spinner, and the like can also be used.

Subsequently, as shown in FIG.
The conductive thin film 2 is subjected to a forming process by an energizing process.
The electron emission portion 25 is formed at the position 4. According to the energization forming, it is possible to locally form a portion of the conductive thin film 24 where the structure is changed such as destruction, deformation or alteration. The end of the energization forming process can be detected by applying a voltage that does not locally destroy or deform the conductive thin film 24 and measuring the current. For example, the device current flowing when a voltage of about 0.1 V is applied is measured, and when the resistance value obtained by the measurement indicates 1 MΩ or more, the energization forming is terminated.

It is preferable to perform an activation process on the element after the forming. By performing the activation process,
The element current If and the emission current Ie change significantly. The activation treatment is performed, for example, in an atmosphere containing a gas of an organic substance.
Similar to the energization forming, it can be performed by repeating the application of the pulse. This atmosphere can be formed using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. The preferable gas pressure of the organic substance at this time varies depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the design.

Suitable organic substances include alkane, alkene, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, aminos, phenols, carboxylic acids, sulfonic acids and the like. Acids and the like can be mentioned. Specifically, methane, ethane,
Saturated hydrocarbons represented by CnH2n2 such as propane, unsaturated hydrocarbons represented by a compositional formula such as CnH2n such as ethylene and propylene, benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, Phenol, formic acid, acetic acid, propionic acid and the like can be used.

By the activation 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 significantly changed. The end of the activation step is determined while measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse crest value, etc. are set as appropriate.

Carbon or a carbon compound is HOPG (H
ily Oriented Pyrolytic
Graphite), PG (Pyrolytic Gr)
aphite), GC (G1assy Carbon)
(HOPG is a graphite having a substantially complete crystal structure, PG is a graphite having a crystal grain of about 200 angstroms and has a slightly disordered crystal structure, and GC is a graphite having a crystal grain of about 20 angstroms and the disorder of the crystal structure is further increased. Amorphous carbon (carbon containing amorphous carbon and a mixture of amorphous carbon and graphite microcrystals), and preferably has a film thickness of 500 Å or less, and 300 Å or less. Is more preferable.

The electron-emitting device obtained through the activation step is preferably subjected to a stabilization treatment. This treatment is preferably performed at a partial pressure of the organic substance in the vacuum vessel of 10 ⁻⁸ torr or less, preferably 10 ⁻¹⁰ torr or less. The pressure in the vacuum vessel is from 10 ^−6.5 torr to 10 ⁻⁷ torr.
And particularly preferably 10 ⁻⁸ torr or less. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element.

Specifically, a vacuum pumping device such as a sorption pump or an ion pump can be used. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. The vacuum evacuation conditions in the heated state at this time are desirably 5 hours or more at 80 to 200 ° C., but are not particularly limited to these conditions, and various conditions such as the size and shape of the vacuum vessel and the configuration of the electron-emitting device. It changes with. The partial pressure of the organic substance is determined by measuring the partial pressure of organic molecules having a mass number of 10 to 200 and mainly containing carbon and hydrogen by a mass spectrometer, and integrating the partial pressures.

The atmosphere at the time of driving after the stabilization step is preferably the same as the atmosphere at the end of the stabilization process, but is not limited to this. If the organic substance is sufficiently removed, Even if the degree of vacuum itself is slightly reduced, sufficiently stable characteristics can be maintained. By employing such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, and as a result, the device current If and the emission current Ie
Becomes stable.

Various arrangements of the 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 rows of electron-emitting devices are arranged (called a row direction), and a direction perpendicular to the wiring (called a column direction). There is a ladder-type arrangement in which a control electrode (also called a grid) disposed above the electron-emitting device controls and drives electrons from 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 commonly connected to a wiring in the X direction. One example is one in which the other of the electrodes of a plurality of electron-emitting devices arranged in the same column is commonly connected to a wiring in the Y direction. Something like this
This is a so-called simple matrix wiring. The simple matrix wiring will be described in detail below.

The m X-direction wirings are Dx1, Dx2,.
Dxm, and can be composed of a conductive paste formed by a printing method. The material, thickness, and width of the wiring are appropriately designed. Y direction wiring is Dy1, Dy2,
To Dyn, and are formed in the same manner as the X-direction wiring. An interlayer insulating layer is provided between the m X-directional wirings and the n Y-directional wirings to electrically separate them (m and n are both positive integers). The interlayer insulating layer is made of, for example, an insulating paste formed by using a printing method. For example, the substrate is formed in a desired shape on the entire surface or a part of the substrate on which the X-directional wiring is formed, and the film thickness, material, and manufacturing method are set so as to withstand the potential difference at the intersection of the X-directional wiring and the Y-directional wiring. . The X-direction wiring and the Y-direction wiring are led out as external terminals. A pair of electrodes constituting the surface conduction electron-emitting device are electrically connected to m X-directional wirings, n Y-directional wirings, and a connection made of a conductive metal or the like.

The materials constituting the wiring and the materials constituting the pair of device electrodes may have some or all of the same or different constituent elements. These materials are appropriately selected, for example, from the above-described materials for the device electrodes.
When the material forming the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be called an element electrode.

Scanning signal applying means for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices arranged in the X direction is connected to the X-direction wiring. On the other hand, a modulation signal generating means for modulating each row of the surface conduction electron-emitting devices arranged in the Y direction in accordance with an input signal is connected to the Y direction wiring. This relationship can be reversed. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device. In the above configuration, individual elements can be selected and driven independently using a simple matrix wiring.

The image display panel using the electron sources having the simple matrix arrangement described above has a structure like the display panel shown in FIG. FIG. 6 shows an example of a display panel of a simple matrix in which the shape of the wiring drawing pattern of the sealing portion is different from that of the display panel shown in FIG.

In FIG. 6, a rear plate 31 on which a plurality of electron-emitting devices are arranged, a face plate 32 in which a fluorescent film and a metal back are formed on the inner surface of a glass substrate, and a support frame 33 arranged between these plates are provided. To form an airtight container. The support frame 34 is baked at a temperature range of 400 to 500 ° C. for 10 minutes or more in air or nitrogen, for example, and sealed. The X-direction wiring and the Y-direction wiring connected to the pair of device electrodes of the surface conduction electron-emitting device are connected to lead lines 34 and 35, respectively. Leader 3
Nos. 4 and 35 have a pattern bent at the sealing portion, and this shape can further improve the airtightness.

In the above-described airtight structure employed in the display panel of the present invention, the insulating layer provided for preventing leakage in the lead-out wiring is formed by printing an interlayer insulating layer between the lower wiring and the upper wiring. It may be formed at the same time. In this case, the insulating layer and the interlayer insulating layer are made of the same material. If there is a problem with the material, it may be formed separately. In any case, the insulating layer provided to prevent the leakage of the lead-out wiring and the insulating layer provided to adhere the support frame are integrated to have an effect as a cover for the lead-out wire, and the glass component is contained in the lead-out wiring. It has the effect of filling the micropores by infiltration.

The width of the frit of the support frame can be increased, but in this case, there are restrictions such as an increase in accuracy and pressure when bonding the panels. In addition, experience has shown that the effect of permeating into the gaps between the metal particles after firing cannot be expected much with only the frit alone. Therefore, as the insulating layer having the two-layer structure as described above, the material applied to the lead wire and the support frame is different. The most effective way to prevent leaks.

The panel formed as described above is evacuated through an exhaust pipe by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating the panel.
After the atmosphere of an organic substance having a degree of vacuum of about 1 × 10 ⁻⁷ torr is made sufficiently small, sealing is performed. In order to maintain the degree of vacuum after sealing, gettering can be performed. This is a process in which a getter disposed at a predetermined position in the panel is heated by heating using resistance heating, high-frequency heating, or the like immediately before or after sealing the panel to form a vapor-deposited film. The getter is usually composed mainly of Ba or the like,
Due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵ to 1 ×
A vacuum degree of 10 ⁻⁷ torr is maintained.

An example of a display panel which actually adopts an airtight structure in which a rear plate and a support frame are bonded and sealed by a two-layer insulating layer, which is a feature of the present invention, will be described below. 1-4 are given.

Example 1 This display panel uses a surface conduction electron-emitting device and matrix wiring, and the structure of the sealing portion of the rear plate is the same as that shown in FIG. The rear plate 11 was a blue glass substrate, and an element electrode 16 was formed by printing and firing an organic metal paste (MOD) on the substrate. The material of the element electrode 16 is made of a 500 angstrom Pt thin film, and the electrode interval is 20 μm and the electrode width is 300 μm at the center.

The X-direction wiring (lower wiring) was printed with Ag @ 1st ink (4045 manufactured by Noritake Co., Ltd.).
It is a printed wiring obtained by baking around ℃, thickness of about 7μ,
The width is 100 μm. The X-direction wiring (lower wiring) is connected to a part of the device electrode. The lead wiring 12b was also formed by the same method.

The interlayer insulating layer for insulating the upper and lower wirings is made of PbO
Glass paste containing Noritake 77 (a product of Noritake Co., Ltd.)
23B) is an insulator formed by firing at about 480 ° C. after printing, and is formed so as to cover an intersection with a Y-direction wiring (upper wiring) to be formed later. The thickness of this interlayer insulating layer is about 25 μm.

The Y-direction wiring (upper wiring) is printed with Ag @ 1st ink (4045 manufactured by Noritake Co., Ltd.) and then printed.
This is a printed wiring obtained by baking at about 0 ° C., crosses the X-directional wiring (lower wiring) on the insulator, and is connected to the element electrode. The thickness of this Y-direction wiring is about 7 μm. The lead wiring 12a was also formed by the same method.

After arranging the matrix, a part of the support frame and 1 mm
The insulating layer 13 (an insulating layer for preventing leakage of the lead-out wiring) was formed at a position where it overlapped by using a screen printing method. The thickness of the insulating layer 13 is about 10 μm, and its material is the same as the above-mentioned glass paste.

The rear plate 1 manufactured as described above
1, a support frame and a face plate, each having an insulating layer (frame frit) of about 100 μm thickness applied on both sides, are attached to each other.
After pre-baking, sealing was performed by a heat treatment at 410 ° C. A blue plate glass was used for the substrate of the face plate.
The phosphor is classified into red (R), edge (G), and blue (B) colors. A slurry in which a phosphor is mixed with a photosensitive resin is applied to a substrate, baked, and then subjected to photolithography. It was formed by patterning. The phosphor may be formed using a printing method.

[0086] The metal back was produced by performing ferming on the phosphor, forming an aluminum thin film having a thickness of about 300 angstroms by vacuum evaporation, and then reducing the film by firing.

After arranging the above in a vacuum panel, a voltage is applied to the X-direction wiring (lower wiring) and the Y-direction wiring (upper wiring) to conduct a current between the element electrodes 16, and a crack-like electron emitting portion is formed. I got Thereafter, an electron extraction voltage of 10 kV was applied using the metal back as an anode electrode, and a voltage of 14 V was applied from the device electrode to the electron emission portion through the XY wiring electrode, whereby electrons were emitted. By irradiating the emitted electrons to the phosphor and adjusting the emitted electrons, the phosphor was allowed to emit light at an arbitrary intensity and the image layer could be displayed.

In this embodiment, the rear plate 11 is
The size is 0 cm square, and the number of electron-emitting devices is 360 × 3
When the inside of the 60 matrix-shaped panels was evacuated, no vacuum leak defect occurred due to the outgoing lines of the X-direction wiring (lower wiring) and the Y-direction wiring (upper wiring).

(Example 2) FIG. 7 is a diagram schematically showing the structure of a sealing portion of the entire rear plate of a display panel according to a second embodiment of the present invention. 3 shows a face plate arranged opposite to the above. In the hermetic structure of the first embodiment, the insulating layer 13 is
In the present embodiment, as shown in FIG. 7, the insulating layer formed on the lead wire further extends from the sealing portion to the inside of the hermetic container. It was configured as follows.

A blue plate glass is used for the rear plate 11,
A 4000 ° thick SiO 2 film was formed thereon by CVD. Further, an Ag paste composed of metal particles was printed thereon by a printing method, and upper and lower wirings (the same material as in Example 1) having a thickness of about 10 μm were formed on each of them. At this time,
A 24 μm-thick interlayer insulating layer (the same material as in Example 1) was formed between the upper and lower wirings so that the upper and lower wirings did not short-circuit.

Thereafter, the insulating layer 13a extends from the sealing portion of the lead wires 12a and 12b to the inside of the hermetic container over the lead wires.
Of 12 μm. Here, the insulating layer 13a needs to be designed so that a portion of the sealing portion that contacts the frame frit is at least 0.2 mm or more. The reason for this is that it is necessary to consider the alignment accuracy at the time of applying the frit, the printing accuracy of the insulating layer, and the like (the same applies to the first embodiment).

The width (length) of the insulating layer 13a on the lead wire may be up to the vicinity of the element portion, but in the case of an electron emission type element, it is necessary to consider the charge amount of electrons. In the present embodiment, it is formed at a distance of 5 mm from the element portion in consideration of edge discharge and safety.

The subsequent steps were the same as in Example 1 to form a face plate and a bonded panel. The display panel formed in this manner had no vacuum leak defect, and a highly reliable display panel was obtained.

Example 3 FIG. 8 is a view schematically showing the structure of a sealing portion of the entire rear plate of a display panel according to a third embodiment of the present invention. 3 shows a face plate arranged opposite to the above. In the present embodiment, the insulating layer formed on the lead wire is configured to spread from the sealing portion of the support frame in both directions inside and outside the airtight container.

For the rear plate 11, a soda lime glass is used.
A 7000 ° thick SiO 2 film was formed thereon by a sputtering method. Further, an Ag paste made of metal particles was formed thereon by a printing method to form upper and lower wirings (the same material as in Example 1) having a thickness of about 8 μm. At this time, an interlayer insulating layer (the same material as in Example 1) having a thickness of 27 μm was formed between the upper and lower wirings so as not to cause a short circuit between the upper and lower wirings.

Thereafter, an insulating layer 13b having a thickness of 15 μm was formed from the sealing portions of the lead wires 12a and 12b to the inside and outside of the hermetic container. In this case, the insulating layer 13b may be formed on the entire area under the frame frit to which the support frame 14b of the sealing portion is bonded, or may be formed only on both ends of the frame frit. Here, a method of contacting only at both ends (a method in which an insulating layer is not provided at the center of the frame frit) is adopted, and the portion in contact with the frame frit is at least 1 mm or more.

The width (length) of the insulating layer 13b inside the hermetic container on the lead wires 12a and 12b may be up to the vicinity of the element portion. However, in the case of the element of the electron emission type as in the second embodiment, the charge amount of electrons You also need to consider. Therefore, in this embodiment, the insulating layer 13b is
Was formed at a distance of 5 mm from the element portion.

The subsequent steps were the same as in Examples 1 and 2 to form a face plate and a bonded panel. The display panel thus formed did not have a vacuum leak defect, and could be a highly reliable display panel.

(Embodiment 4) The display panel of this embodiment has the same structure as the hermetic structure described in Embodiment 1 (see FIG. 3), but the manufacturing procedure is different.

For the rear plate 11, a soda-lime glass is used.
A 4000 ° thick SiO 2 film was formed thereon by CVD. Further, on this, upper and lower wirings were formed to a thickness of about 10 μm using an Ag paste made of metal particles by printing or photolithography. At this time, thickness 2
At the same time as forming the 3 μm interlayer insulating layer, the insulating layer 13 on the lead wire contacting the frame frit is also formed.

In order to form the insulating layer 13 at the same time as described above, it is necessary to form at least the lead wire of the upper wiring at the region where the insulating layer 13 is formed when forming the lower wiring. At this time, when forming the upper wiring, connection with the lead wire formed in advance, or
It is necessary to pay attention to the disconnection of the wiring in the interlayer insulating layer.

In this embodiment, the portion of the insulating layer 13 which comes into contact with the sealing portion is at least 1 mm as in the other embodiments.
That is all.

In the subsequent steps, a face plate and a bonded panel were formed in the same manner as in Example 1.
The display panel thus formed did not have a vacuum leak defect, and could be a highly reliable display panel.

[0104]

As described above, according to the present invention,
Since the leak in the lead wire can be reduced,
It is possible to provide a highly reliable display panel in which the inside of the panel is maintained at a high vacuum, which has not been achieved in the past.

[Brief description of the drawings]

FIG. 1 is a sectional structural view showing an example of an airtight structure of a sealing portion between a rear plate and a support frame of a display panel of the present invention.

FIG. 2 is a perspective view showing one configuration example of a display panel of the present invention.

FIG. 3 is a schematic diagram showing a structure of a sealing portion of an entire rear plate of the display panel having the airtight structure shown in FIG. 1;

FIGS. 4A and 4B are schematic diagrams showing a basic structure of a surface conduction electron-emitting device provided in a display panel of the present invention, wherein FIG. 4A is a plan view and FIG.

FIGS. 5A to 5C are process cross-sectional views illustrating a method for manufacturing a surface conduction electron-emitting device.

FIG. 6 is a schematic diagram showing an example of a wiring lead pattern of the display panel of the present invention.

FIG. 7 is a schematic diagram illustrating a structure of a sealing portion of an entire rear plate of a display panel according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a structure of a sealing portion of an entire rear plate of a display panel according to a third embodiment of the present invention.

FIG. 9 is a diagram schematically showing a typical example of a surface conduction electron-emitting device.

FIG. 10 is a schematic diagram showing a pattern shape of a lead line of a vacuum sealing portion of a display panel described in JP-A-9-277586.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear plate 2 Thick film wiring 3, 4 Insulating layer 5 Support frame

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C012 AA05 5C032 FF05 FF06 FF07 5C036 EE17 EF01 EF06 EF09 EG05 EG33 EG34 EG50 EH06 EH26 5C094 AA31 BA32 CA19 CA24 DA14 DB01 DB04 EA04 EA05 EB02 EC03 GB03

Claims (7)

[Claims] 1. A display panel comprising: a plate in which at least a part of an airtight container constituting a panel is formed by sealing a plate on which a thick film lead line made of metal particles is formed and a support frame for supporting the plate; A display panel, wherein a lead wire is drawn from the inside of the hermetic container to the outside of the container, and at least a space between the lead wire portion and the support frame is sealed with first and second insulating layers. 2. The display panel according to claim 1, wherein said first insulating layer is configured to seal said plate and said support frame, and said second insulating layer is formed of said first insulating layer. A display panel provided in contact with an insulating layer and configured to cover a sealing portion of the lead wire. 3. The display panel according to claim 2, wherein the second insulating layer is made of a material capable of impregnating the lead wire. 4. The display panel according to claim 2, wherein the second insulating layer is provided so as to overlap with the first insulating layer, and the inside of the container, the outside of the container, or both sides from the first insulating layer. A display panel, wherein the display panel is provided to extend over the display panel. 5. The display panel according to claim 2, wherein a row-direction wiring and a column-direction wiring are provided on the plate, and the interlayer insulating layer is provided at a portion where the row-direction wiring and the column-direction wiring overlap. A display panel, wherein the second insulating layer is made of the same material. 6. A panel sealing method for forming a hermetic structure by sealing a support frame supporting a plate to a plate provided with a thick film lead line made of metal particles, comprising: Sealing the plate and the support frame using a layer, and sealing the portion of the lead wire that is sealed by the first insulating layer by further using a second insulating layer. Characteristic panel sealing method. 7. The panel sealing method according to claim 6, wherein a material capable of impregnating the lead wire is used as a material of the second insulating layer.