JP2000251722A - Sealing method of image display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing method of an image display device capable of simply realizing a getter activation at a lower temperature for a shorter time by causing a damage which a non-evaporation getter receives at the time of sealing less and serving as the getter activation step by a vacuum baking step. SOLUTION: The image display device is provided with an electron source; an image display member for an image by an electron released from the electron source; and a non-evaporation getter 18 in an air tight container and a joining of each constitution member of the air tight container is carried out by a heat molten seal material 21. In the sealing method of the device, at least one portion or a whole portion or area at which the non-evaporation getter 18 is accommodated in the image display device is controlled to a temperature below a sealing temperature. A group including at least one kind of gas selected from an inert gas, a nitrogen gas and a hydrogen gas is flowed into the image forming device and the seal material 21 is heated and molten to the sealing temperature to seal it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sealing an image forming apparatus, and more particularly, to a method for sealing a flat type image forming apparatus using a cold cathode electron emission source using frit glass (low melting glass). About the method.

[0002]

2. Description of the Related Art Conventionally, when manufacturing an image forming apparatus for maintaining the inside of a vacuum, a frit glass having a seal shape is applied or placed between glass members and placed in a sealing furnace such as an electric furnace. Alternatively, a sealing method is adopted in which the entire image forming apparatus is placed on a hot plate heater (in some cases, sandwiched between the hot plate heaters from above and below) to a sealing temperature and the glass member at the sealing portion is fused with sealing glass. Have been.

Further, a flat type image forming apparatus using an electron source requires an ultra-high vacuum in order to stably operate a cold cathode electron-emitting device or the like for a long time, so that a substrate having a plurality of electron-emitting devices is required. And a getter that seals a substrate having a phosphor at a position opposed thereto with a frit glass with a frame interposed therebetween, adsorbs emitted gas and maintains vacuum.

[0004] There are two types of getters: a vapor deposition type and a non-evaporation type. The vapor deposition type getter heats an alloy containing Ba or the like as a main component in a vacuum glass envelope by energization or high frequency, and deposits a vapor deposition film on the inner wall of the container. Is formed (getter flash), and the gas generated inside is adsorbed by the active getter metal surface to maintain a high vacuum. Non-evaporable getters include Ti, Zr,
By arranging a getter material such as V, Al, Fe or the like and performing “getter activation” to obtain gas adsorption characteristics by heating in a vacuum, the released gas can be adsorbed.

In general, a flat-type image forming apparatus is thin and cannot be provided with a deposition area or a flash area for 10 minutes because of the thinness of the vapor deposition type getter, and is installed near a support frame outside an image display area.
Therefore, the conductance between the central portion of the image display and the getter installation region is reduced, and the effective pumping speed at the central portion of the electron-emitting device or the phosphor is reduced. In an image forming apparatus having an electron source and an image display member, a portion for generating a gas is an image display area mainly irradiated by an electron beam. Therefore, when it is desired to maintain the phosphor and the electron source in a high vacuum, it is necessary to arrange a non-evaporable getter in the vicinity of the phosphor and the electron source that are the emission gas generating sources. In the case of a conventional CRT, the conductance between the phosphor and the getter film is considerably larger than that of a flat-type image forming apparatus. for that reason,
The effective pumping speed is considerably higher than that of the flat type image forming apparatus. Therefore, the gas emitted from the phosphor by the electron irradiation is effectively exhausted by the getter region in the CRT, so that the gas emitted from the phosphor is quickly adsorbed and exhausted by the getter, and the pressure in the CRT is reduced to a flat image. It can be kept lower than the forming apparatus.

Further, since there is a getter film around the electron source, an extreme pressure rise does not occur even by the gas emitted from the electron source itself.

[0007] The generated gas deteriorates the electron source or the phosphor and is driven for a long time, so that the brightness of the image forming and displaying part is reduced. Further, a part of the generated gas is ionized to cause a discharge, which may destroy the electron source.

In view of such circumstances, US Pat.
No. 453,659 "Anode Plate for
Flat Panel Display having
Integrated Getter ”, issur
ed 26 Sept. 1995 to Wallac
e et al. Discloses a technique in which a getter member is formed in a gap between stripe-shaped phosphors on an image display member (anode plate). In this example, the getter material is electrically separated from the phosphor and the conductor electrically connected to the phosphor, so that an appropriate potential is applied to the getter to irradiate and heat the electrons emitted from the electron source. Then, the getter is activated.

Heretofore, two types of electron-emitting devices using a thermionic electron-emitting device and a cold-cathode electron-emitting device have been known. Field emission type (hereinafter, referred to as “FE type”) cold metal electron emitting devices, metal / insulating layer /
There are a metal type (hereinafter, referred to as "MIM type"), a surface conduction electron-emitting device, and the like. As an example of the FE type, W. P. Dy
ke & W. W. Dolan, "Field emiss
ion ", Advance in Electron
Physics, 8, 89 (1956) or C.I.
A. Spindt, “PHYSICAL Proper
ties ofthin-film field em
issue cathodes with molly
bdenium cones ", J. Appi. Phys.
s. , 47, 5248 (1976).

As an example of the MIM type, C.I. A. Mead,
“Operation of Tunnel-Emis
site Devices, ”J. Apply. Phys.
s. , 32, 646 (1961).

Examples of the surface conduction electron-emitting device type include:
M. I. Elinson, Recio Eng. Ele
ctron Phys. , 10, 1290, (196
5) and the like.

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film [G. Dittmer: “Thin Solid Fi
lms ", 9,317 (1972)] , In 2 O 3 / S
nO ₂ thin film [M. Hartwell and
C. G. FIG. Fontad: "IEEE Trans. E
D Conf. "519 (1975)], using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 2
2 (1983)].

A flat panel image type display device which emits a phosphor by an electron beam generated from these cold cathode electron-emitting devices has been developed. A surface conduction electron-emitting device emits electrons by passing a current through a conductive thin film having a high resistance part in one part. An example of such a device is disclosed in Japanese Patent Application Laid-Open No. 7-235255. It is shown.

[0014]

However, the conventional method for sealing an image forming apparatus has the following disadvantages.

As described above, in the flat-type image forming apparatus, the non-evaporable getter is arranged near the phosphor or the electron source which is the source of the emitted gas. When a conventional sealing method of heating the entire glass envelope other than the sealing portion to the sealing temperature and fusing the frit glass of the sealing portion is taken, the non-evaporable getter is adversely affected at the time of sealing, There was a drawback that the conditions for "getter activation" for obtaining the later adsorption characteristics became more severe. That is, if the sealing temperature of the non-evaporable getter-provided region is high, the non-evaporable getter is damaged, and the getter must be activated by heating at a higher temperature later to obtain the adsorption characteristics. . At this time, for example, as described in the above-mentioned US Pat. No. 5,453,659, an appropriate potential is applied to the getter to irradiate and heat the electrons emitted from the electron source, It is necessary to separately provide a heating means and a step. Further, in some getters having a low activation temperature, if the sealing temperature of the non-evaporable getter area is high, the getter cannot be activated and almost no adsorption characteristics can be obtained.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the prior art, the present invention makes it possible to reduce the damage to a non-evaporable getter at the time of sealing, and to easily activate the getter at a lower temperature or for a shorter time. More preferably, it is an object of the present invention to provide a method of sealing an image forming apparatus in which a vacuum baking step indispensable for a manufacturing step of a glass envelope for maintaining a vacuum inside can also serve as a getter activating step.

[0017]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems of the conventional sealing method for an image display device and to achieve the object of the present invention. It has been completed.

That is, the present invention provides: (1) an image comprising at least a rear plate on which an electron-emitting device serving as a phosphor excitation means is arranged, and a face plate on which a phosphor emitting light by the phosphor excitation means is arranged; A non-evaporable getter is provided in the display device,
In the sealing method for an image display device, wherein the bonding between the rear plate and the face plate is bonded via a support and a sealing material, at least a part or all of the non-evaporable getter-provided region in the image display device Is controlled to a temperature lower than the sealing temperature, and a gas containing at least one gas selected from an inert gas, a nitrogen gas, and a hydrogen gas is flowed into the image display device, and the sealing material is heated and melted to the sealing temperature. (2) A sealing method for an image display device, wherein the sealing material according to the above (1) is a glass frit; (3) (1) The method for sealing an image display device according to (1), wherein the means for heating and melting the sealing material to the sealing temperature is direct heating by optical means; (5) a method of sealing an image display device, wherein the means for heating and melting the sealing material to the sealing temperature is direct heating for energizing and heating a metal foil or a metal film disposed directly adjacent to the sealing material; (6) The method for sealing an image display device according to (1), wherein the means for heating and melting the sealing material to the sealing temperature is indirect heating via a support, a face plate, or a rear plate; (1) The method for sealing an image display device according to (1), wherein the region of the electron-emitting device is controlled to a temperature lower than a sealing temperature; A method of sealing an image display device, wherein the sealing method is an electron-emitting device or a field-emission electron-emitting device.

The airtight container includes an electron source, an image forming member for forming an image by electrons emitted from the electron source, and a non-evaporable getter. In the sealing method of the image forming apparatus is joined by a heat-fusible sealing material, controlling at least a part or the whole area of the non-evaporable getter provided area in the image forming apparatus to a temperature lower than the sealing temperature, Further, a gas containing at least one gas selected from an inert gas, a nitrogen gas, and a hydrogen gas flows into the image forming apparatus, and the sealing material is heated and melted to a sealing temperature for sealing. It is also a sealing method for the image forming apparatus.

[0020]

According to the sealing method of the image display device of the present invention, the temperature of the non-evaporable getter at the time of sealing can be made lower than the sealing temperature, so that damage can be prevented. Further, by performing the process in an inert gas atmosphere for the non-evaporable getter, the deterioration of the non-evaporable getter can be further suppressed. Furthermore, since the gas released at the time of sealing can be quickly discharged to the outside of the non-evaporable getter region by flowing the gas, the atmosphere of the non-evaporable getter can be improved, and damage to the non-evaporable getter can be reduced. Can be suppressed. By doing so, the getter activation conditions for obtaining the subsequent adsorption characteristics become easier, and the getter activation can be easily performed at a lower temperature or in a shorter time. As a result, deterioration in luminance due to long-time driving is suppressed, and a stable image display device can be provided.

[0021]

Embodiments of the present invention will be described below. Since the essence of the present invention relates to a sealing method for an image forming apparatus, the present invention is not limited to a sealing method for an image display apparatus using a surface conduction type or field emission type electron emitting element, but uses an electron emitting element. Needless to say, the method can be applied to the sealing method of the image forming apparatus. Further, as the image forming member, a phosphor for displaying an image or an image forming member for forming a latent image can be used.

[Embodiment 1] In this embodiment, a plurality of surface conduction electron-emitting devices, which are cold cathode electron-emitting devices, are formed on a rear plate as electron-emitting devices, and a fluorescent screen (face plate) is used as an image forming member. Was installed, and a color image display device having an effective display area of 15 inches diagonally and a length to width ratio of 3: 4 was prepared. First, an image display device of the present invention will be described with reference to FIGS. 2 and 3, and then a method of manufacturing the image display device will be described.

FIG. 2 is a perspective view of the image display device used in the present embodiment, and a part of the panel is cut away to show the internal structure.

In FIG. 1, reference numeral 1 denotes a face plate, 8 denotes a rear plate, and 9 denotes a support frame. 1, 8 and 9 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling the airtight container, it is necessary to seal the members in order to maintain sufficient strength and airtightness for joining the members.

In the drawing, reference numeral 7 denotes an exhaust pipe on the gas introduction side when the inert gas flows at the time of sealing, and is an exhaust pipe for connecting to a vacuum device when evacuating the airtight container to a vacuum. Further, these exhaust pipes are also used as a gas introduction pipe for an activation gas in an activation step generated during a process step.

In the drawing, reference numeral 7 'denotes an exhaust pipe on the gas outlet side when an inert gas flows during sealing.

In the figure, reference numeral 16 denotes a Ba evaporation type getter for maintaining a vacuum in the airtight container after sealing the exhaust pipe. B
The a-evaporable getter forms a Ba vapor-deposited film by heating to a high temperature. The Ba vapor deposition film is a very active film and is an excellent vacuum pump having an adsorption / exhaust ability for gases other than the inert gas.

On the rear plate 8, N × M surface conduction electron-emitting devices 19 are formed. (N and M are positive integers of 2 or more and are appropriately set according to the target number of display pixels.) In the N × M surface-conduction emission devices, M column-directional wirings 12 (lower wirings) ) And N row-direction wirings 14
(Also referred to as upper wiring) to form a simple matrix wiring.

Further, a non-evaporable getter 18 is arranged on the upper wiring.

Next, description will be made with reference to FIG. FIG. 3 is a schematic diagram showing the configuration of the surface conduction electron-emitting device.
19 is shown. FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along the line AA ′ in FIG. FIG.
8 is a rear plate (substrate), 11 (a) and 11
(B) is an element electrode, 15 is a conductive thin film, and 20 is an electron emitting portion.

By forming the conductive thin film 15 through the device electrodes 11 (a) and 11 (b) while evacuating the airtight container through the exhaust pipe 7, the forming process is performed.
Locally destroy, deform or alter the conductive thin film,
Forming an electron emitting portion 20 in an electrically high resistance state,
Further, when the pressure in the hermetic container becomes 1 × 10 ⁻³ Pa or less, about 1 Pa of acetone is introduced as an activating gas through the exhaust pipe 7 into the hermetic container to perform an activating step for remarkably improving the emission current. A voltage is applied to the device electrodes 11 (a) and 11 (b) of the conduction electron-emitting device and a current flows through the device, thereby activating the above-described electron-emitting portion 20 (see the description of the prior art). (Similar to the example disclosed in Japanese Unexamined Patent Publication No. Hei 7-235255).

The phosphor screen (face plate) 1 is composed of a glass substrate, a transparent conductive film ITO, a phosphor, and a metal back of aluminum. In this embodiment, the ITO film is formed on the face plate.
It does not necessarily have to be provided. In this embodiment, since the present embodiment is a color display device, phosphors of three primary colors of red, green and blue used in the field of CRT are separately applied to the portion of the phosphor 4. The phosphors of the three primary colors are separated by black stripes.

Dx1 to Dxm, Dy1 to Dyn, and Hv are terminals for electrical connection of an airtight container provided for electrically connecting the display panel to an electric circuit (not shown). Dx1 to Dxm are column wiring 1 of the multi-electron beam source.
2 and Dy1 to Dyn are the row wirings 14 of the multi-electron beam source.
And Hv are electrically connected to the metal back 3 of the phosphor screen.

The image display device to which the manufacturing method of the present invention is applied has been described above.

Next, a method for manufacturing an image display device according to the present invention will be described with reference to FIGS. FIG.
FIG. 2 is a diagram showing a sealing method of the image display device of the present embodiment, FIG. 2 is a perspective view of the image display device used in the present embodiment, and FIG. 3 is a configuration of a surface conduction electron-emitting device. FIG.

(Preparation of Rear Plate) (R-1) The blue plate glass is washed, and the device electrode 11 is formed on the rear plate 8 on which the silicon oxide film 17 is formed by sputtering.
(A) and 11 (b) were formed by offset printing.
The lower wiring 12 was formed by screen printing. Next, an interlayer insulating film 13 is formed between the lower wiring 12 and the upper wiring 14. Further, the upper wiring 14 was formed.

(R-2) Next, a conductive thin film 15 made of PdO is formed by sputtering, and then patterned.
It was in the desired form.

(R-3) Further, a getter member 18 (ribbon getter) having a non-evaporable getter formed on the nichrome ribbon was fixed on the upper wiring with an inorganic adhesive. In this embodiment, the main components of the non-evaporable getter are Zr, V, Mn, and the like, but are not limited thereto.

Through the above steps, a rear plate having a surface conduction type emission element, a non-evaporable type getter, etc., formed by simple matrix wiring was prepared.

(R-4) Put the rear plate in a vacuum device and evacuate it. When the pressure becomes 0.1 Pa or less, a voltage is applied to the electron-emitting device through the external terminals Dox1 to Doxm and Doy1 to Doyn. The forming step was performed on the conductive thin film 15.

(Preparation of Support Frame) (W-1) A frit glass 21 (a) for bonding the support frame and the face plate is formed on the side surface of the support frame 9 in contact with the face plate by a printing method.

(Formation of Face Plate) (F-1) An SiO ₂ layer and an ITO film were formed on a blue glass substrate 1 by a sputtering method, and a phosphor and a black conductor were formed by a printing method. Perform the smoothness treatment of the inner surface of the fluorescent film,
Thereafter, Al was deposited using a vacuum deposition method or the like to form a metal back.

(F-2) A frit glass 21 (c) for fixing an exhaust pipe to a through hole for exhaust formed on the face plate is formed by a printing method.

(Adhesion of Support Frame, Face Plate, and Exhaust Pipe) (WFH-1) The support frame 9, the face plate 1, and the exhaust pipes 7, 7 'are aligned and fixed to a fixing jig (not shown). At this time, the frit glass 21 (a) is set so as to be between the support frame 9 and the face plate.

(WFH-2) This was put into an electric furnace, and
The temperature was raised to 0 ° C at 20 ° C per minute,
Then, the temperature was lowered to room temperature at 20 ° C./min.

(WFH-2) A frit glass 21 (b) for sealing with the rear plate is formed on the support frame in contact with the rear plate again by a printing method.

Through the above steps, the face plate having the phosphor, the support frame, and the exhaust pipe are integrated.

(Preparation of Airtight Container by Sealing Integrated Rear Plate and Supporting Frame / Face Plate / Exhaust Pipe) Referring to FIG. 1, gas flow sealing for controlling the non-evaporable getter section 18 to a temperature lower than the sealing temperature. The steps will be described.

(FR-1) The rear plate is held on a hot plate 22 on an X, Y, θ adjustment stage (not shown), and an integrated object (support frame / face plate / exhaust pipe) is placed on a hot plate 22 '. To hold.

The gas flow system is connected to the exhaust pipe. In this embodiment, Ar gas was used as the introduction gas. The gas flow system includes a heater 25 for controlling the heating of the gas introduced into the introduction system.
And a device for controlling the flow rate by the mass flow controller 26 are arranged. The gas flow state is monitored by the mass flow meter 27. At this time, the alignment between the rear plate and the integrated object (support frame / face plate / exhaust pipe) is performed on the X, Y, and θ adjustment stages, and the support frame and the rear plate are brought into contact with each other and pressurized.

(FR-2) The mass flow controller 2 controls the flow rate of Ar gas into the image display device to be 5 slm.
6. The unit and the rear plate are controlled by the hot plates 22 and 22 'on the stage up to 300.degree.
Heated at ° C. Thus, the sealing temperature (at 400 ° C. or higher,
Heating the members constituting the image display device at a temperature less than (determined by the frit type) is referred to as assist heating. The temperature at that time is called an assist temperature. The assist heating is heating for suppressing heat distribution for preventing the glass from cracking due to thermal strain. At this time, the flow gas was heated by the heater 25 in synchronization with the temperature of the hot plate simultaneously with the heating of the hot plate, and was controlled to 300 ° C.

(FR-3) After the image display device is controlled to be heated to 300 ° C., the laser light 24 is scanned and irradiated by the laser 23 to be absorbed by the frit glass 21 (b) and locally heated to the sealing temperature. Do. The laser used in the present invention includes a semiconductor laser, a carbon dioxide gas laser, a YAG laser, and the like. Any laser can be used as long as it has a wavelength that transmits glass but is absorbed by a black or gray sealing material. is there. Laser irradiation light passes through the glass,
The frit glass is heated and melted, and the glass member is fused. The sealing temperature of the frit glass is generally 400 ° C. or higher and is determined by the type of the frit glass. In this embodiment, the frit glass having a sealing temperature of 410 ° C. was used.

(FR-4) After irradiating the frit glass 21 (b) with the laser beam 24 in all around scan. Thereafter, the temperature of the hot plate was lowered to room temperature at 20 ° C. per minute. At this time, the temperature of the introduced gas was also lowered synchronously.

(FR-5) When the temperature of the image display device reached room temperature, the flow of the introduced gas was stopped.

As described above, the image display device was sealed in the non-evaporable getter area by heating at a lower temperature than before.

(Preparation of Electron Emitting Element by Vacuum Process) (S-1) First, an exhaust pipe 7 'used for gas flow sealing.
Was heated and melted and sealed. The exhaust pipe 7 is connected to a vacuum exhaust device (not shown), and the inside of the image display device is exhausted to a vacuum.

(S-2) Subsequently, when the pressure in the image display apparatus becomes 1 × 10 ⁻³ Pa or less, acetone as an activating gas is introduced into the airtight container through the exhaust pipe 7 at 1 Pa.
A voltage was applied to the electron-emitting device through the external terminals Dox1 to Doxm and Doy1 to Doyn to perform an activation process.

(Degassing Step in Image Display Apparatus) (D-1) After activating gas is sufficiently exhausted, baking degassing processing of the image display apparatus is performed. The baking temperature was 300 ° C. The heating rate was 2 ° C. per minute.

(D-2) The temperature of the image display device is 300 ° C.
For 10 hours. This vacuum baking step serves not only for degassing in the image display device but also for activating the non-evaporable getter. Then, the temperature is lowered to room temperature, and B
The evaporable getter 16 was flashed by high-frequency heating from outside the image display device to form a Ba deposited film.

(D-3) Thereafter, a part of the exhaust pipe 7 was melted and heated and sealed.

[Comparative Example 1] In order to confirm the effect of the image display device produced in Example 1, an airtight container was prepared by sealing (integrally of the rear plate and the support frame / face plate / exhaust pipe) in Example 1 In the process, without gas flow,
In addition, the sealing was not performed by local heating with a laser beam, but was heated to the sealing temperature by the upper and lower hot plates 22, 22 'to perform the sealing step of the image display device.

As described above, even if the non-evaporable getter portion in the image display device is subjected to the sealing step at a temperature lower than the sealing temperature, cracks do not occur even after a high-temperature process such as vacuum baking. It was confirmed that vacuum tightness was maintained without any problem. Further, with respect to driving for a long time, a temporal change in luminance at the central portion of the image display was measured. The driving conditions of Example 1 and Comparative Example 1 were exactly the same. The driving conditions of the electron source are
The whole screen was driven by scrolling Dox1 to Doxm with DC + 7.5V, Doy1 to Doyn with voltage -7V, pulse width 30μS, and frequency 60Hz. The acceleration voltage of the face plate is 6 kV. FIG. 4 shows the measurement results. The horizontal axis shows the drive time, and the vertical axis shows the luminance normalized under the initial conditions. It should be noted that there was no difference in the absolute value of the initial luminance between Example 1 and Comparative Example 1. From FIG. 4, it was found that the image display device created in this embodiment can be operated stably without deterioration in luminance for a long time. The reason why it is possible to operate stably is that the degree of vacuum at the center of the image display has been improved. This is because the non-evaporable getter could be activated in the vacuum baking step without deteriorating in the sealing step.

Actually, the total pressure gauge was installed at the center of the face plate to check the degree of vacuum improvement at the center of the image display device by measuring the driving pressure. The following study was performed to measure the pressure. In (Formation of face plate) (F-2) of the first embodiment, a through hole is newly formed in the center of the phosphor of the face plate of the image display device of FIG. 2, and a frit for fixing an exhaust pipe is printed. did. Further, the (weld of the support frame, the face plate, and the exhaust pipe) (WFH-1), the exhaust pipe for mounting the total pressure gauge is newly aligned and fixed to the fixing jig. Thereafter, after the bonding step, the total pressure gauge was connected to the exhaust pipe so as to attach the total pressure gauge. The other steps and the image display device were the same as in Example 1 and Comparative Example 1 to produce an image display device. This image display device
FIG. 5 shows the result of monitoring the change in the total pressure during the same driving as described above. In the figure, the abscissa indicates the driving time, and the non-driving measurement was performed for 10 minutes as a background, and then the same driving as described above was performed. The vertical and horizontal directions show the total pressure normalized by the total pressure of the comparative example when not driven. From this figure, it can be seen that in the present embodiment, the pressure during non-driving is lower than that of the conventional example, and the pressure during driving is also lower. From this fact, it can be seen that the non-evaporable getter in this embodiment is suppressed from deteriorating in the sealing step and is effectively activated in the vacuum baking step.

[Embodiment 2] In this embodiment, a plurality of surface conduction electron-emitting devices, which are cold cathode electron-emitting devices, are formed on the rear plate as electron-emitting devices in the same manner as in Embodiment 1.
A color image display device having a fluorescent screen (face plate) and an effective display area of 15 inches diagonally and a length to width ratio of 3: 4 was prepared.

A method of manufacturing an image display device according to the present invention will be described with reference to FIGS.

(Preparation of Rear Plate) (R-1) The blue plate glass is washed, and the device electrode 11 is formed on the rear plate 8 on which the silicon oxide film 17 is formed by sputtering.
(A) and 11 (b) were formed by offset printing.
The lower wiring 12 was formed by screen printing. Next, an interlayer insulating film 13 is formed between the lower wiring 12 and the upper wiring 14. Further, the upper wiring 14 was formed.

(R-2) Next, a conductive thin film 15 made of PdO is formed by sputtering, and then patterned.
It was in the desired form.

(R-3) Further, a portion other than the upper wiring was covered with a metal mask, and a non-evaporable getter 18 was laminated on the upper wiring 14 by plasma spraying to a thickness of about 50 μm. The main components of the non-evaporable getter used in this embodiment are Ti, Zr, V, Fe
etc. However, the present invention is not limited to this.

Through the above steps, a rear plate having a surface conduction type emission element, a non-evaporation type getter and the like formed with simple matrix wiring was prepared.

(R-4) Put the rear plate in a vacuum device and evacuate it. When the pressure becomes 0.1 Pa or less, a voltage is applied to the electron-emitting device through the outer terminals Dox1 to Doxm and Doy1 to Doyn. The forming step was performed on the conductive thin film 15.

(Preparation of Support Frame) (W-1) A frit glass 21 (a) for bonding the support frame and the face plate is formed on the side surface of the support frame 9 in contact with the face plate by a printing method.

(Formation of Face Plate) (F-1) An SiO ₂ layer and an ITO film were formed on a blue glass substrate 1 by a sputtering method, and a phosphor and a black conductor were formed by a printing method. Perform the smoothness treatment of the inner surface of the fluorescent film,
Thereafter, Al was deposited using a vacuum deposition method or the like to form a metal back.

(F-2) A frit glass 21 (c) for fixing an exhaust pipe in a through hole for exhaust formed in the face plate is formed by a printing method.

(Adhesion of Support Frame, Face Plate, and Exhaust Pipe) (WFH-1) The support frame 9, the face plate 1, and the exhaust pipes 7, 7 'are aligned and fixed to a fixing jig (not shown). At this time, the frit glass 21 (a) is set so as to be between the support frame 9 and the face plate.

(WFH-2) This was put into an electric furnace, and
The temperature was raised to 0 ° C at 20 ° C per minute,
Then, the temperature was lowered to room temperature at 20 ° C./min.

(WFH-3) On the side in contact with the rear plate, a metal foil 28 for electric heating for directly heating the sheet frit 21 (b) is arranged around the circumference except for the current introduction terminal portion.

(WFH-4) Next, frit glass 21 (b) for sealing with the rear plate is formed on the metal foil 28 by a printing method so as to cover the metal foil.

Through the above steps, the face plate having the phosphor, the support frame, and the exhaust pipe are integrated.

(Preparation of Airtight Container by Sealing Integrated Rear Plate and Supporting Frame / Face Plate / Exhaust Pipe) Referring to FIG. 6, gas flow sealing for controlling the non-evaporable getter section 18 to a temperature lower than the sealing temperature. The steps will be described.

(FR-1) The rear plate is held on a hot plate 22 on an X, Y, θ adjustment stage (not shown), and an integrated object (support frame / face plate / exhaust pipe) is placed on a hot plate 22 ′. To hold.

The gas flow system is connected to the exhaust pipe. In this embodiment, Ar / 2% H2 gas was used as the introduced gas. In the gas flow system, a heater 25 for heating and controlling the gas introduced into the introduction system and a device for controlling the flow rate by the mass flow controller 26 are arranged. The gas flow state is monitored by the mass flow meter 27. At this time, the alignment between the rear plate and the integrated object (support frame / face plate / exhaust pipe) is performed on the X, Y, and θ adjustment stages, and the support frame and the rear plate are brought into contact with each other and pressurized.

(FR-2) Ar / 2% into the image display device
The mass flow controller 26 controls the flow rate of the H2 gas to 5 slm, and the unit and the rear plate are heated to an assist temperature of 300 ° C. by a hot plate 22 on the stage.
And at 22 'at 20 ° C per minute. At this time, the flow gas was heated by the heater 25 in synchronization with the temperature of the hot plate simultaneously with the heating of the hot plate, and was controlled to 300 ° C.

(FR-3) After the image display device is controlled to be heated to 300 ° C., an electric current is supplied from a current introducing terminal portion (not shown) of the electric heating wire 28 so that the frit glass 21 (b) is turned on.
It was locally heated to 50 ° C. In this embodiment, frit glass having a sealing temperature of 450 ° C. using frit glass was used.

(FR-4) After the frit glass 21 (b) was melted, the temperature was gradually lowered and held at 410 ° C. for 10 minutes to perform a distortion removing step. Thereafter, the electric power supplied to the heater for energization heating was reduced to zero. Thereafter, the temperature of the hot plate was lowered to room temperature at 20 ° C. per minute. At this time, the temperature of the introduced gas was also lowered synchronously.

(FR-5) When the temperature of the image display device reached room temperature, the flow of the introduced gas was stopped.

As described above, the image display device was sealed in the non-evaporable getter-provided area by heating at a lower temperature than before.

(Preparation of Electron Emitting Element by Vacuum Process) (S-1) First, the exhaust pipe 7 'used for gas flow sealing.
Was heated and melted and sealed. The exhaust pipe 7 is connected to a vacuum exhaust device (not shown), and the inside of the image display device is exhausted to a vacuum.

(S-2) Subsequently, when the pressure in the image display device becomes 1 × 10 ⁻³ Pa or less, acetone as an activating gas is introduced into the airtight container through the exhaust pipe 7 at 1 Pa.
A voltage was applied to the electron-emitting device through the external terminals Dox1 to Doxm and Doy1 to Doyn to perform an activation process.

(Degassing Step in Image Display Apparatus) (D-1) After sufficiently activating the activation gas, baking degassing processing of the image display apparatus is performed. The baking temperature was 350 ° C. The heating rate was 2 ° C. per minute.

(D-2) The temperature of the image display device is 350 ° C.
For 10 hours. This vacuum baking step serves not only for degassing in the image display device but also for activating the non-evaporable getter. Then, the temperature is lowered to room temperature, and B
The evaporable getter 16 was flashed by high-frequency heating from outside the image display device to form a Ba deposited film.

(D-3) Thereafter, a part of the exhaust pipe 7 was melted and heated and sealed.

Comparative Example 2 In order to confirm the effect of the image display device produced in Example 2, the frit glass used in Comparative Example 1 was changed to a sealing temperature of 450 ° C. In the step of producing an airtight container by sealing the support frame / face plate / exhaust pipe integrated body), the entire image display apparatus is sealed with a hot plate at a sealing temperature of 450 ° C.
The process was changed to the process of controlling and sealing until the image forming apparatus was formed.

As described above, even if the non-evaporable getter portion in the image display device is subjected to the sealing step at a temperature lower than the sealing temperature, cracks and the like do not occur through a high-temperature process such as vacuum baking. It was confirmed that there was no vacuum tightness.
Further, with respect to driving for a long time, a change with time of electron emission of the electron-emitting device at the central portion of the image display was measured. The driving conditions of Example 2 and Comparative Example 2 were exactly the same. The long drive conditions of the electron source are as follows: Dox1 to Doxm + 7.5V DC,
Doy1 to Doyn are driven with a voltage of -7 V, a pulse width of 30 μS, a frequency of 60 Hz, and the whole screen is driven by scrolling. After 100 hours,
After 500 hours, 1000 hours, and 2,000 hours, the entire scrolling is stopped and the image display central portion 10 × 1
Only the 0 element was driven for 1 minute, and the amount of electron emission was measured. At this time, the acceleration voltage of the face plate is 8 kV. FIG. 7 shows the measurement results. The abscissa indicates the drive time, and the ordinate indicates the value obtained by standardizing the average value of the electron emission amount of the 10 × 10 elements in the central portion of the image display device by the initial value. It should be noted that there was no difference between the absolute values of the initial average electron emission amounts of Example 2 and Comparative Example 2. From FIG. 7, it was found that the image display device manufactured in this example can be operated stably with little deterioration of the electron source for a long time. The reason why it is possible to operate stably is that the degree of vacuum at the center of the image display has been improved. This is because the non-evaporable getter could be activated in the vacuum baking step without deteriorating in the sealing step. In this example, it is considered that the activation of the non-evaporable getter was better because the vacuum baking was at a high temperature.

Embodiment 3 In the third embodiment of the present invention, an image forming apparatus having the structure shown in FIG. 8 was prepared. In this embodiment, a plurality of field emission devices, which are cold cathode electron emission devices, are formed on the rear plate as electron emission devices, and spacers 10 are used as atmospheric pressure support members to further reduce the weight.
8 were installed. The phosphor plate 102 is provided on the face plate.
And a color image forming apparatus having an effective display area of 10 inches diagonally and a length to width ratio of 3: 4 was prepared. First, a sealing method of the image display device of the present invention will be described with reference to FIG. In FIG. 8 (and FIG. 9), 103 is a rear plate, 101 is a face plate, 105 is a cathode,
6 is a gate electrode, 107 is an insulating layer between the gate and the cathode, 1
09 is a non-evaporable getter. In FIG. 9, 110
Is a frit glass for bonding the face plate 101 and the support frame 104, and 110 'is a frit glass 110' for bonding the rear plate 103 and the support frame 104 similarly. The face plate 10
1. The gap between the rear plates 103 is 1.5 mm.
Reference numeral 112 denotes a non-evaporable getter. In this embodiment, the non-evaporable getter is composed of Zr, V and Fe. However, the non-evaporable getter may be mainly composed of Ti and is not particularly limited thereto.

Next, a method for manufacturing the image display device of the present invention will be described with reference to FIGS.

(Preparation of Rear Plate) (R-1) The blue plate glass was washed, and
The cathode (emitter) 105 and the gate electrode 10 shown in FIG.
6. Wiring and the like were created. The cathode material was Mo.

(R-2) A non-evaporable getter 109 having a thickness of 50 μm was formed on the gate electrode 106 by plasma spraying.

(R-3) After the non-evaporable getter 109 and the spacer 108 were positioned on the rear plate, they were fixed with an inorganic adhesive.

Through the above steps, a rear plate on which a field emission type emission device, a non-evaporation type getter, a spacer, and the like formed by simple matrix wiring were formed.

(Preparation of Support Frame) (W-1) A frit glass 110 for bonding the support frame and the face plate is printed on the side surface of the support frame 104 that contacts the face plate (the upper surface of the support frame in FIG. 9). Formed by method.

(W-2) Frit glass 11 for bonding the support frame and the face plate to the side surface of the support frame 104 that contacts the rear plate (the lower surface of the support frame in FIG. 5).
0 'is formed by a screen printing method.

(Formation of Face Plate) (F-1) A phosphor and a black conductor were formed on a blue plate glass by a printing method. A smoothing treatment was performed on the inner surface of the fluorescent film, and then Al was deposited by using a vacuum evaporation method or the like to form a metal back.

(F-2) A frit for bonding the exhaust pipe to the face plate is formed by a screen printing method.

(Adhesion of Faceplate and Exhaust Pipe) (WFH-1) Faceplate 101, Exhaust Pipe 11
1, 111 'is aligned and fixed to a fixing jig (not shown).

(WFH-2) This was put in an electric furnace, and
The temperature was raised to 0 ° C at 20 ° C per minute,
Then, the temperature was lowered to room temperature at 20 ° C./min.

(Preparation of Airtight Container by Sealing Rear Plate, Support Frame and Face Plate) A gas flow sealing step for controlling the non-evaporable getter section 109 to a temperature lower than the sealing temperature will be described with reference to FIG.

(FR-1) The rear plate is held on hot plates 120 'and 121' on an X, Y, and θ adjustment stage (not shown), and the support frame 104 is placed on the rear plate.
Place. The faceplate attached to the exhaust pipe is 120,
It is held at 121. The hot plate includes upper and lower 120 and 120 'for assist heating and 121 and 12 for sealing heating.
1 '. Heater for assist heating 12
0, 120 'controls the temperature of the non-evaporable getter 109,
Sealing heaters 121 and 121 'are made of frit glass 1
This is a heater for melting and heating 10,110 '.

The gas flow system is connected to the exhaust pipe. In this embodiment, Ar gas was used as the introduction gas. The gas flow system includes a heater 25 for controlling the heating of the gas introduced into the introduction system.
And a device for controlling the flow rate by the mass flow controller 26 are arranged. The gas flow state is monitored by the mass flow meter 27. At this time, the alignment between the rear plate and the face plate is performed on the X, Y, and θ adjustment stages, and the face plate, the support frame, and the rear plate are brought into contact with each other and pressurized.

(FR-2) The mass flow controller 2 was introduced into the image display device so that the flow rate of Ar gas became 2 slm.
The heating was performed at 20 ° C./min on the hot plates 120 and 120 ′ on the stage up to 350 ° C. as assist heating. At the same time, the sealing heaters 121, 121 '
The temperature was also raised to 350 ° C. in synchronization. At this time, at the same time as the heating of the hot plate, the flow gas was also heated by the heater 25 in synchronization with the temperature of the hot plate, and was controlled to 350 ° C.

(FR-3) After the heating of the image display apparatus is controlled to 350 ° C., the frit glass 110, 110 ′ is sealed at 450 ° C. by the sealing heaters 121, 121 ′.
The temperature was raised to In this embodiment, frit glass having a sealing temperature of 450 ° C. using frit glass was used.

(FR-4) Frit glass 110, 11
After melting 0 ′, the temperature was gradually lowered and held at 410 ° C. for 10 minutes to perform a strain removing step. Thereafter, the temperature of the sealing heater was lowered to the same temperature as the assist heater, and then the temperature of all the hot plates was lowered to room temperature at 20 ° C./min. At this time,
The temperature of the introduced gas was also lowered synchronously.

(FR-5) When the temperature of the image display device reached room temperature, the flow of the introduced gas was stopped.

As described above, the non-evaporable getter-provided area was sealed with the image display device by heating at a lower temperature than before.

(Vacuum Process) (S-1) First, the exhaust pipe 11 used for gas flow sealing is used.
A portion of 1 'was melted by heating and sealed. The exhaust pipe 111 is connected to a vacuum exhaust device (not shown), and the inside of the image display device is exhausted to a vacuum.

(Degassing Step in Image Display Apparatus) (D-1) When the pressure in the hermetic container becomes 1 × 10 ⁻⁴ Pa or less, the non-evaporable getter 112 is heated by an external high-frequency heating device. Degassing and activation of the non-evaporable getter. The activation temperature of the non-evaporable getter is determined by the non-evaporable getter. In the present embodiment, the heating treatment is performed at 500 ° C. for 5 minutes.

(D-2) Next, baking and degassing of the airtight container is performed. The baking temperature was 350 ° C. The heating rate was 2 ° C. per minute.

(D-3) When the temperature of the airtight container is 1
At the stage of holding for 0 hours, a part of the exhaust pipe 110 was heated and melted to seal.

(D-4) After the sealing is completed, the airtight container is set at 2 / min.
Cool at ℃ and cool to room temperature.

[Comparative Example 3] In order to confirm the effect of the image display device produced in Example 3, the same structure and steps as those in Example 3 were carried out (the airtight container by sealing the rear plate, the support frame and the face plate). Preparation) An image forming apparatus was formed by changing the process of controlling and sealing the entire image display apparatus to a sealing temperature of 450 ° C. using an assist heater and a sealing heater.

As described above, even if the non-evaporable getter portion in the image display device is subjected to the sealing step at a temperature lower than the sealing temperature, no crack or the like is generated even after passing through a high temperature process such as vacuum baking. It was confirmed that vacuum tightness was maintained without any problem. In addition, the number of discharges for 100 hours of the initial driving of the electron source was measured. The driving conditions were the same for Example 3 and Comparative Example 3. The gate voltage was set to +120 V, and the acceleration voltage of the metal back was set to 500 V.

[0121]

[Table 1] From Table 1, it was found that the image display device manufactured in this example can be stably operated with little discharge.
The reason for the stable operation is that the non-evaporable getter can be activated in the vacuum baking process without deteriorating in the sealing process, and the number of discharges has been reduced because the gas released during driving was removed. Seem.

[0122]

According to the method of sealing an image display device of the present invention, it is possible to suppress damage at the time of sealing a non-evaporable getter. This facilitates the getter activation conditions for obtaining the subsequent adsorption characteristics, and the getter activation can be performed in a normal vacuum baking process. Thereby, it is possible to suppress the deterioration of the cold cathode electron source and also prevent the deterioration of the phosphor. In addition, it is possible to suppress the discharge caused by the gas and prevent the electron source from being damaged by the discharge.
As a result, deterioration in luminance due to long-time driving can be suppressed, and a stable image display device can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a sealing method of an image display device according to an embodiment.

FIG. 2 is a perspective view of the image display device used in the present embodiment.

FIG. 3 is a schematic diagram illustrating a configuration of a surface conduction electron-emitting device.

FIG. 4 is a diagram showing a change over time in luminance of Example 1 and Comparative Example 1.

FIG. 5 is a diagram showing pressures of the image display devices of Example 1 and Comparative Example 1.

FIG. 6 is a diagram illustrating a sealing method of the image display device according to the second embodiment.

FIG. 7 is a graph showing the change over time in the average electron emission amount in Example 2 and Comparative Example 2.

FIG. 8 is a schematic diagram showing a configuration of a field emission type electron emission element.

FIG. 9 is a diagram illustrating a sealing method of the image display device according to the third embodiment.

[Explanation of symbols]

1,101 Face plate 7,7 ', 111,111' Exhaust pipe 8,103 Rear plate 9,104 Outer frame 21 (a), 21 (b), 110,110 'Frit glass 16 Evaporation type getter 112 Ring type non- Evaporation type getter 19 Surface conduction type emission element 12 Column direction wiring (lower wiring) 13 Insulation layer between lower wiring and upper wiring 14 Row direction wiring (upper wiring) 102 Phosphor (metal back) 11 (a), 11 (b) ) Device electrode 15 Conductive thin film 20 Electron emission section 105 Cathode 106 Gate electrode 107 Gate / cathode insulating layer 108 Spacer 18, 109 Non-evaporable getter 19, 22 ', 120, 120' Assist heating hot plate 23 Laser light source 24 Laser light 25 Inlet gas heater 26 Mass flow controller 27 Mass flow meter 28 Frit Heating metal foil heater 121 and 121 'frit indirect heating for hot plate place

Claims (7)

[Claims] 1. An electron source in an airtight container, and an image forming member for forming an image by electrons emitted from the electron source,
A non-evaporable getter, wherein the components of the hermetic container are joined by a hot-melt sealing material. Controlling at least a part or the entire region to a temperature lower than the sealing temperature, and flowing into the image forming apparatus a gas containing at least one gas selected from an inert gas, a nitrogen gas, and a hydrogen gas, A sealing method for an image forming apparatus, wherein a sealing material is heated and melted to a sealing temperature and sealed. 2. An image forming apparatus comprising at least a rear plate on which an electron-emitting device serving as a phosphor excitation means is disposed and a face plate on which a phosphor emitting light by the phosphor excitation means is disposed. A mold getter, wherein the rear plate and the face plate are joined to each other through a support and a sealant. At least a part or the whole area is controlled to a temperature lower than the sealing temperature, and a gas containing at least one gas selected from an inert gas, a nitrogen gas, and a hydrogen gas flows into the image forming apparatus, and the sealing is performed. A sealing method for an image forming apparatus, wherein a material is heated and melted to a sealing temperature and sealed. 3. The sealing method for an image forming apparatus according to claim 1, wherein the sealing material is frit glass. 4. The sealing method for an image forming apparatus according to claim 1, wherein the means for heating and melting the sealing material to a sealing temperature is direct heating by an optical means. 5. The method according to claim 1, wherein the means for heating and melting the sealing material to a sealing temperature is direct heating for energizing and heating a metal foil or a metal film disposed directly adjacent to the sealing material. 3. The method for sealing an image forming apparatus according to item 2. 6. The image forming apparatus according to claim 1, wherein the means for heating and melting the sealing material to the sealing temperature is indirect heating via a support, a face plate, or a rear plate. Sealing method. 7. The method according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device or a field emission electron-emitting device.