JPH1064429A - Manufacture of image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the vacuum condition of a sealed container for a long time, and to prevent the deterioration in electron-emitting performance by releasing air through plural air evacuated pipes connected to a sealed container, while performing baking, and thereafter, sealing the evacuated pipes except for one evacuated pipe, and flashing type getter arranged inside of the sealed container. SOLUTION: Plural evacuated pipes 8, 9 are connected to a sealed container formed by connecting a face plate 1, a rear plate 2 and an insulating outer frame 3 with the low-melting point glass. The residual gas inside the sealed container is evacuated through these evacuated pipes 8, 9 to 1×10<-5> Torr or lower, and foaming is performed so as to form a (Pbo) thin film 14 with an electron-emitting part 15. Active gas is led through the evacuated pipe 8 so as to activated element electrodes 12, 13, and thereafter, vacuum high- temperature baking is performed so as to seal the evacuated pipe 8. After the baking, the evaluated pipe 9 is sealed, and thereafter induction heating is performed so as to activate the getter 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an image display device using an electron beam.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices, EL display devices, and plasma display panels (PDPs) have been put to practical use as flat-panel image display devices. However, these image display devices are inferior to commonly used cathode ray tubes (CRTs) in view angle, contrast ratio, and luminance.

For this reason, as an image display device, several electron beam acceleration type flat panel displays have been proposed. Among them, as an element capable of obtaining electron emission with a simple structure, for example, MI Elinson (MIE)
Linson) et al. are known [Radio Engineering Electron.
Physis (Radio. Eng. Electron.
Phys. ) Volume 10, pages 1290-1296, 196
5 years].

This utilizes a phenomenon in which an electron is emitted when a current flows in a thin film having a small area formed on a substrate in parallel with the film surface, and is generally called a surface conduction electron-emitting device. Have been.

As the surface conduction electron-emitting device, a device using a SnO ₂ thin film developed by Elinson et al. Or a carbon thin film [Hisashi Araki et al .: “Vacuum”, Vol. 26, No. 1, , P. 22, (1983)].

[0006] These surface conduction electron-emitting devices have the advantages that they have a simple structure, are easy to manufacture, and are suitable for large-area electron sources in which a large number of devices are arranged on a substrate.

A conventional method for manufacturing a flat panel type image display device using a planar cold cathode as the surface conduction electron-emitting device will be described below. Before showing a method of manufacturing the image display device, its structure will be described with reference to the drawings.

FIG. 2 shows an image display device using a surface conduction electron-emitting device. As shown in the figure, this image display device has a face plate 1 as an image display surface made of an insulating material such as glass, a rear plate 2 arranged opposite to the face plate 1, and an insulating material made of glass or the like. The outer frame 3 is joined with low-melting glass at the peripheral portions of the face plate 1 and the rear plate 2 to form an airtight container. The pressure applied to the airtight container from outside is determined by the outer frame 3
And the atmospheric pressure support column 7 to keep the distance between the face plate 1 and the rear plate 2 constant. On the face plate 1, a phosphor 4 and an aluminum thin film 5 are formed.
1 kV by an external high voltage power supply (not shown)
A high voltage of ~ 10 kV is applied. Reference numeral 8 denotes an exhaust pipe for introducing a gas to be introduced at the time of the activation process and also for exhausting the airtight container. The introduced activation gas activates the electron-emitting device 6. Reference numeral 9 denotes an exhaust pipe for exhausting the airtight container, which is connected to a vacuum pump via a valve. Reference numeral 10 denotes a getter provided to maintain the degree of vacuum in the container after sealing the airtight container, and 11 denotes preventing the getter material from diffusing into the image display area when the getter material is flashed (activated). It is a shielding plate for performing.

FIG. 3 shows a surface conduction electron-emitting device which is an electron source of an image display device. The electron source has device electrodes 12 and 13 formed on a rear plate 2, and the electrodes are arranged at a constant interval (about 2 μm). Element electrode 1
An organic palladium thin film 14 is formed on 2 and 13, and a crack formed in a central portion of the organic palladium thin film serves as an electron emitting portion 15.

A method for manufacturing the above-described image display device will be described. An element portion is formed on the rear plate 2 in advance. The element portion includes wiring, element electrodes 12 and 13, Pd
It is composed of an O (palladium oxide) thin film 14. The getter 10 and the atmospheric pressure support column 7 are fixed by firing low-melting glass on the rear plate 2 on which the element section is formed. A junction between the rear plate 2 on which the electron-emitting device 6, the getter 10 and the atmospheric pressure support column 7 are formed, the peripheral portion of the face plate 1 on which the phosphor 4 and the aluminum thin film 5 are formed, and the outer frame 3 Is coated with a low melting glass. Around the outer frame 3, there are provided pipes 8 and 9 for introducing or exhausting gas, and a low-melting glass is also applied to the installation sections. These members are sealed by firing the low-melting glass to complete an airtight container.

FIG. 5 is a flowchart showing a manufacturing process for completing the image display device through the getter flash process after sealing.

After all the members are sealed, the residual gas in the airtight container is exhausted from the pipes 8 and 9. When the pressure in the hermetic container reaches about 1 × 10 ⁻⁵ Torr or less, a forming process (voltage application to the device electrodes 12 and 13) is performed to form the electron emission portions 15 on the PdO thin film 14. Thereafter, when the pressure in the airtight container reaches about 5 × 10 ⁻⁷ Torr or less,
An activation gas is introduced through the pipe 8 and exhausted from the pipe 9 so that the pressure in the airtight container becomes 4 × 10 ⁻⁶ Torr, and the element is activated. The activation process is a process of introducing an activation gas into an airtight container and applying a pulse voltage between device electrodes. By performing this activation process, electron emission increases, and the luminance of the image display device improves. After the activation of the device, a vacuum high-temperature baking process is performed to perform a degassing process. The temperature of the airtight container is raised to 200 ° C. and maintained for 5 to 10 hours. Thereafter, the temperature is lowered to room temperature. Then, after sealing the tubes 8 and 9, the getter 10 is flashed (activated) by induction heating. The getter 10 has an exhausting effect. By activating the getter 10, the residual gas in the hermetic container is captured, and the inside of the hermetic container is maintained at a high vacuum for a long time.

In order for the above-mentioned image display device to operate stably for a long time, it is necessary to maintain the vacuum in the hermetic container as high as possible for as long as possible.

Since the total exhaust amount of the getter is limited, in order to extend the vacuum maintenance time in the airtight container as much as possible,
It is important to minimize the amount of gas released from the hermetic container during a getter flush. Further, it is necessary to reduce the gas emitted during getter flash as much as possible. Generally, in order to drive out the gas adsorbed on the getter material, a method is employed in which the getter material is heated at 300 to 350 ° C. for several minutes in an evacuated state. further,
Japanese Patent Application Laid-Open No. Hei 4-277440 describes a method for reducing the amount of gas released during a getter flash (especially a rare gas such as Ar) as much as possible and maintaining the vacuum maintenance time in an airtight container for a long time. This is because the getter is heated at a temperature higher than the maximum temperature of the airtight container and lower than the activation temperature of the getter during the high-temperature baking exhaust, and the rare gas such as argon adsorbed on the getter is desorbed and exhausted. Is the way. This prevents generation of a rare gas such as argon when the getter is activated after the sealing is cut.

In general, there is one exhaust pipe for evacuating the airtight container, but in some cases, two or more exhaust pipes are provided as in the above-described image display device. This is to improve the conductance of the exhaust to shorten the exhaust time to a high vacuum state, or to facilitate the gas introduction when introducing the gas into the airtight container.

[0016]

In the case where there are two or more exhaust pipes (including gas introduction) as described above, the number of times of sealing the exhaust pipe is increased as compared with one exhaust pipe. This also increases the amount of outgassed gas generated in the sealing and cutting process. Naturally, the gas generated in the sealing and cutting step adheres to the inside of the airtight container, and the airtight container that has been degassed by the baking process is contaminated. As much gas is generated,
It is sufficient to increase the amount of the getter, but since the getter is usually incorporated in the getter flash area as much as possible, increasing the amount of the getter increases the size of the entire image display device. In order to reduce the size and weight of the image display device as much as possible, even if the number of exhaust pipes increases, it is necessary not to increase the amount of gas adhering in the airtight container accompanying the sealing and cutting process. Furthermore, in the manufacture of an image display device using a surface conduction electron-emitting device, an electron source that has been subjected to an activation process by introducing an organic gas and subjected to an activation process to easily emit electrons is an oxygen source generated in a sealing and cutting process. In addition, problems such as deterioration due to highly reactive gas such as water, emission of electrons being suppressed, and deterioration of image display capability also occur.
A highly reactive gas such as oxygen or water in an airtight container can be adsorbed and exhausted by exhausting with a getter for a long time, but a considerable amount of time is required before the electron emission characteristics of the surface conduction type electronic element do not deteriorate. It is.

Therefore, in the present invention, the gas generated in the sealing and cutting step adheres to the hermetic container, thereby limiting the amount of getter adsorbed, and the time for maintaining a high vacuum in the hermetic container is not shortened. Another object of the present invention is to provide a method of manufacturing an image display device that minimizes generation of gas that causes deterioration of an electron source of the image display device.

[0018]

Means for Solving the Problems The present invention for solving the above problems is as follows. 1. In a method of manufacturing an image display device having an airtight container, a step of baking while exhausting the inside of the airtight container through an exhaust pipe connected to the airtight container, a step of sealing the exhaust pipe, and a step of being disposed in the airtight container Flushing the getter, wherein a plurality of the exhaust pipes are connected to the airtight container, and at least one of the exhaust pipes is sealed during the baking step, and the remaining exhaust pipe is sealed after the baking step. And then maintaining the vacuum in the container by a step of flashing the getter. 2. In a method of manufacturing an image display device having an airtight container, a step of baking while exhausting the inside of the airtight container through an exhaust pipe connected to the airtight container, a step of sealing the exhaust pipe, and a step of being disposed in the airtight container Flushing the getter, wherein a plurality of the exhaust pipes are connected to the hermetic container, and at least one of the exhaust pipes is sealed during the baking step, and after the baking step is completed, the getter is flushed and then the sealing is left. A method of manufacturing an image apparatus, comprising: maintaining a vacuum in a container by sealing an exhaust pipe of (1). 3. A step of introducing an activating gas into the hermetic container from the exhaust pipe before the baking step.
Or the method for manufacturing an image device according to item 2. 4. 4. The method for manufacturing an image device according to any one of the above items 1 to 3, wherein the sealing performed during the baking step is performed at a temperature of 100 ° C. or higher. 5. The exhaust pipe is a glass pipe, and the sealing portion of the exhaust pipe that is not sealed during baking is set at a temperature lower than the softening point of the glass.
5. The method for manufacturing an image device according to any one of 1 to 4, wherein the baking degassing is performed at a temperature of 00 ° C. or higher.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. ADVANTAGE OF THE INVENTION According to the manufacturing method of the image display device of this invention, the number of exhaust pipes connected to the airtight container can be increased to shorten the exhaust time and facilitate gas introduction. ) The amount of gas generated in the process, which remains in the airtight container when the chip-off is completed, can be minimized, so that a high vacuum can be maintained for a long time and the electron emission performance of the surface conduction electron-emitting device does not deteriorate. An image display device can be provided.

[0020]

【Example】

Embodiment 1 FIG. 1 shows a flowchart from the sealing process to the getter flash process in the manufacturing process of the image display device according to the present invention. In FIG. 2 described above, the gap between the face plate 1 and the rear plate 2 is set to 10 mm, and after all the members are sealed, the residual gas in the hermetic container is exhausted from the pipes 8 and 9. When the pressure in the hermetic container reaches about 1 × 10 ⁻⁵ Torr or less, a forming process (voltage application to the device electrodes 12 and 13) is performed to form the electron emission portions 15 on the PdO thin film 14. Thereafter, when the pressure in the airtight container reaches about 5 × 10 ⁻⁷ or less, n-hexane is introduced from the tube 8 and exhausted from the tube 9 so that the pressure in the airtight container becomes 4 × 10 ⁻⁶ Torr, The device is activated. In this embodiment and the later-described embodiments, n-hexane is used as the activation gas for the electron-emitting device. However, the present invention is not particularly limited as long as the gas activates the electron-emitting device. As the activating gas species, an organic gas is particularly effective. After the activation of the device, a vacuum high-temperature baking process is performed to perform a degassing process.
The temperature of the airtight container was raised to 200 ° C., and the temperature was usually maintained for 5 to 10 hours, in this example, 10 hours. Immediately before cooling, the tube 8 is sealed off. This first sealing and cutting step performed during the baking step does not necessarily need to be performed during the high-temperature holding time,
If the temperature of the image display device is 100 ° C. or higher, there is an effect. Thereafter, the temperature is lowered to room temperature. Then, after sealing the tube 9, the getter 10 is flashed (activated) by induction heating. The getter 10 has an exhausting effect. By activating the getter 10, the residual gas in the hermetic container is captured, and the inside of the hermetic container is maintained at a high vacuum for a long time. Further, in the present embodiment and later-described embodiments, the Ba-Al-Ni evaporation type is used as the getter material. For example, Ti (titanium), Zr (zirconium),
A getter or the like containing Fe (iron), Ni (nickel), V (vanadium) or the like as a main component may be used, but is not limited thereto. Thus, the image display device is completed.

The operation of the image display device configured as described above will be described below. When a driving pulse voltage is applied to the element electrodes 12 and 13 of the electron-emitting device section by an external drive circuit (not shown) in the image display device maintained at a predetermined degree of vacuum, electrons are emitted from the electron-emitting section 15. The emitted electrons are accelerated by the voltage (1 kV to 10 kV) applied to the phosphor 4 and the aluminum thin film 5 and collide with the aluminum thin film 5. This collision causes the phosphor 4
Is excited, and an image is displayed on the image display surface.

In order to compare the image display device manufactured by the above-described manufacturing method of the present embodiment with the image display device manufactured by the above-described conventional manufacturing method, the element characteristics were evaluated.

A drive voltage between the device electrodes was 15 V, a pulse width of 100 μA, and a cycle of 10 mS was applied. Also,
An acceleration voltage of 4 kV was applied to the phosphor and the aluminum thin film.
Table 1 shows the measurement results of the emission current Ie per element after driving for a certain time at this time.

[0024]

[Table 1] From this result, it can be seen that in the element characteristics of the image display device manufactured by the manufacturing method of the present embodiment, Ie which contributes to the luminance of the image is improved as compared with the conventional example. This is because, in the conventional image display device, the getter's gas adsorbing ability was consumed excessively by the amount of gas generated by the sealing cut of the exhaust pipe, so that the getter's exhaust ability was reduced after a long time driving, and the degree of vacuum was deteriorated. It is considered that the reactive gas such as oxygen and water deteriorated the performance of the electron source. From these values, the effect of the method for manufacturing an image display device according to the present invention is clear.

Embodiment 2 FIG. 4 shows a flowchart from the sealing to the completion of chip-off in the manufacturing process of the image display device according to the present invention. In FIG. 2 described above, the face plate 1 and the rear plate 2
Is set to 10 mm, and after all the members are sealed, the gas remaining in the airtight container is exhausted from the tubes 8 and 9. When the pressure in the hermetic container reaches about 1 × 10 ⁻⁵ Torr or less, a forming process (voltage application to the device electrodes 12 and 13) is performed to form the electron emission portions 15 on the PdO thin film 14. afterwards,
When the pressure in the airtight container reaches about 5 × 10 ⁻⁷ Torr or less, n-hexane is introduced from the pipe 8 and exhausted from the pipe 9 so that the pressure in the airtight container becomes 4 × 10 ⁻⁶ Torr,
The device is activated. After the activation of the device, a vacuum high-temperature baking process is performed to perform a degassing process. The temperature of the airtight container was raised to 200 ° C. and maintained for 10 hours. Tube 8 immediately before cooling
Is cut off. Thereafter, the temperature is lowered to room temperature. Getter 10
Is flashed (activated) by induction heating using the same as in Example 1. The getter 10 has an exhausting effect. By activating the getter 10, the residual gas in the hermetic container is captured, and the inside of the hermetic container is maintained at a high vacuum for a long time. After a lapse of several minutes to one hour from the completion of the flush, the tube 9 is sealed to complete the chip-off.
Thus, the image display device is completed.

In order to compare the image display device manufactured by the above-described manufacturing method of the present embodiment with the image display device manufactured by the above-described conventional manufacturing method, the element characteristics were evaluated under the same conditions as in the first embodiment. went. Table 2 shows the measurement results.

[0027]

[Table 2] From this result, it can be seen that the element characteristics of the image display device manufactured by the manufacturing method of the present embodiment have improved Ie that contributes to the luminance of the image as compared with the conventional example. This is because, in the conventional image display device, the getter's gas adsorbing ability was consumed excessively by the amount of gas generated by the sealing cut of the exhaust pipe, so that the getter's exhaust ability was reduced after a long time driving, and the degree of vacuum was deteriorated. It is considered that the reactive gas such as oxygen and water deteriorated the performance of the electron source. From these values, the effect of the method for manufacturing an image display device according to the present invention is clear.

Embodiment 3 FIG. 5 shows a flowchart from the sealing to the getter flash step in the manufacturing process of the image display device according to the present invention. In FIG. 2 described above, the gap between the face plate 1 and the rear plate 2 is set to 10 mm, and after all the members are sealed, the residual gas in the hermetic container is exhausted from the pipes 8 and 9. When the pressure in the hermetic container reaches about 1 × 10 ⁻⁵ Torr or less, a forming process (voltage application to the device electrodes 12 and 13) is performed to form the electron emission portions 15 on the PdO thin film 14. Thereafter, the pressure in the airtight container is reduced to about 5 × 10 ⁻⁷ To.
When the pressure reaches rr or less, the pressure in the airtight container is 4 × 10 ⁻⁶ T
n-hexane was introduced through tube 8 so that
The air is further exhausted, and the element is activated. After the activation of the device, a vacuum high-temperature baking process is performed to perform a degassing process. The temperature of the airtight container was raised to 200 ° C. and maintained for 10 hours. Immediately before the temperature is lowered, first, a degassing process is performed at 400 ° C. for 2 hours at a chip-off portion of the pipe 9 which is not subjected to the sealing and cutting process during the high temperature baking. Thereafter, the temperature at the tip-off point of the tube 9 is set to 200 ° C.
Then, the tube 8 is sealed off. Thereafter, the temperature of the whole airtight container is lowered to room temperature. Then, after sealing the pipe 9,
The getter 10 (the same one as in Example 1) is flashed (activated) by induction heating. The getter 10 has an exhausting effect. By activating the getter 10, the residual gas in the hermetic container is captured, and the inside of the hermetic container is maintained at a high vacuum for a long time. Thus, the image display device is completed.

In order to compare the image display device manufactured by the above-described manufacturing method of the present embodiment with the image display device manufactured by the above-described conventional manufacturing method, the element characteristics were evaluated under the same conditions as in the first embodiment. went. Table 3 shows the measurement results.

[0030]

[Table 3] From this result, it can be seen that the element characteristics of the image display device manufactured by the manufacturing method of the present embodiment have improved Ie that contributes to the luminance of the image as compared with the conventional example. This is because, in the conventional image display device, the getter's gas adsorbing ability was consumed excessively by the amount of gas generated by the sealing cut of the exhaust pipe, so that the getter's exhaust ability was reduced after a long time driving, and the degree of vacuum was deteriorated. It is considered that the reactive gas such as oxygen and water deteriorated the performance of the electron source. From these values, the effect of the method for manufacturing an image display device according to the present invention is clear.

Further, by performing baking degassing at a temperature lower than the softening point of the glass of the exhaust pipe, the second portion of the exhaust pipe, which is not subjected to the sealing and cutting during baking, is subjected to baking degassing.
Since the gas generated by the sealing and cutting can be reduced, it was also confirmed that the characteristics were further improved for a long time. The first exhaust pipe sealing step does not necessarily need to be performed during the high-temperature holding step during the baking process, and may be performed during the cooling step if the temperature of the image display device is 100 ° C. or higher.

[0032]

According to the present invention described in detail above, the number of exhaust pipes connected to the hermetic container is increased, so that there are advantages such as shortening of exhaust time and facilitation of gas introduction and the like. It is possible to provide a method for manufacturing an image display device which can easily maintain a high vacuum for a long period of time, reduce deterioration of an electron source as an image display device, and can be used for a long time.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a manufacturing process of an image display device of the present invention.

FIG. 2 is a schematic view illustrating the configuration of an image display device.

FIG. 3 is a schematic view of a surface conduction electron-emitting device of the image display device.

FIG. 4 is a flowchart illustrating a manufacturing process of the image display device of the present invention.

FIG. 5 is a flowchart illustrating a manufacturing process of the image display device of the present invention.

FIG. 6 is a flowchart illustrating a manufacturing process of a conventional image display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Face plate 2 Rear plate 3 Outer frame 4 Phosphor 5 Aluminum thin film 6 Electron emission element 7 Atmospheric pressure support column 8 Tube (for exhaust and gas introduction) 9 Tube (for exhaust and gas introduction) 10 Getter 11 Shield plate 12, 13 Device electrode 14 Palladium thin film 15 Electron emission part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location H01J 29/86 H01J 29/86 Z 31/12 31/12 C

Claims (5)

[Claims] 1. A method for manufacturing an image display device having an airtight container, wherein a step of baking while exhausting the inside of the airtight container through an exhaust pipe connected to the airtight container, a step of sealing the exhaust pipe, and an airtight container Flushing a getter disposed therein, wherein a plurality of the exhaust pipes are connected to an airtight container, and at least one of the exhaust pipes is sealed during a baking step, and the exhaust pipe is left unsealed after the baking step. A method for manufacturing an image device, wherein an exhaust pipe is sealed, and thereafter, a vacuum of a container is maintained by a step of flashing a getter. 2. A method for manufacturing an image display device provided with an airtight container, a step of baking while exhausting the inside of the airtight container through an exhaust pipe connected to the airtight container, a step of sealing the exhaust pipe, and a method of sealing the airtight container. Flushing the getters disposed therein, wherein a plurality of the exhaust pipes are connected to the airtight container, and at least one of the exhaust pipes is sealed during the baking step, and the getters are flushed after the baking step is completed. And a method of manufacturing the image device, wherein a vacuum is maintained in the container by sealing the remaining exhaust pipe. 3. The method according to claim 1, further comprising a step of introducing an activation gas into the airtight container from the exhaust pipe before the baking step. 4. The encapsulation performed during the baking step comprises:
2. The method according to claim 1, wherein the heating is performed at a temperature of 00 ° C. or more.
4. The method for manufacturing an image device according to any one of items 3 to 3. 5. The exhaust pipe is a glass pipe, and a sealed portion of the exhaust pipe not sealed during baking is subjected to a baking degassing process at a temperature equal to or lower than the softening point of the glass and equal to or higher than 100 ° C. The method for manufacturing an image device according to claim 1, wherein