JP2000223051A - Manufacture of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an image forming device with no crack generated during getter-heating and with high yield. SOLUTION: In this method for manufacturing an image forming device provided with an electron emitting device, an image forming member, an exhaust pipe, a nonevaporation-type getter or/and a evaporation-type getter, when a getter 1 is activated, a cover 4 for blocking an airtight container 7 from outside air is disposed.

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 forming apparatus using an electron-emitting device, and more particularly to a gettering process for an airtight container.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices using a thermionic electron-emitting device and a cold-cathode electron-emitting device have been known. The cold cathode electron emitting device includes a field emission type (hereinafter, referred to as “FE type”), a metal / insulating layer / metal type (hereinafter, referred to as “MIM type”), a surface conduction type electron emitting device, and the like. As an example of the FE type, W. P. Dyk
e & W. W. Dolan, "Field emis
Ssion ", Advance in Electroro
n Physics, 8, 89 (1956) or C.I. A. Spindt, “PHYSICAL Prop
arts ofthin-film field
emission cathodes with mo
lybdenium cones ", J. Appl. P
hys. , 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 (1965)
And the like.

[0005] 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 a 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 / Sn
O ₂ due to the thin film [M. Hartwell and
C. G. FIG. Fonstad: "IEEE Trans. E
D Conf. "519 (1975)], using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 2
2 (1983)].

[0006] A flat panel display device which emits a phosphor by an electron beam generated from these cold cathode electron-emitting devices has been developed.

The display device requires an ultra-high vacuum in order to stably operate the cold cathode electron-emitting device for a long time. Therefore, a substrate having a plurality of electron-emitting devices and a phosphor at a position facing the substrate are provided. The substrate is sealed by a method described later with a frame interposed therebetween to form a vacuum confidential container.

In fact, as described above, in order to form an electron-emitting device in an airtight container and maintain it as an image forming apparatus, the inside of the airtight container is evacuated by an exhaust pipe connected to the airtight container by a vacuum device. After evacuating to a vacuum and applying means or activation to form an electron source in the airtight container,
After the degassing process in the hermetic container is sufficiently performed by a baking process of maintaining the hermetic container at a high temperature of 300 ° C. to 350 ° C. for several hours or more, the temperature of the hermetic container is lowered to room temperature, and then the image display in the hermetic container is performed. The evaporating getter containing Ba as a main component disposed outside the region is heated or heated at a high frequency to evaporate the Ba material to form a getter film (hereinafter referred to as getter flash), and then heat and melt the exhaust pipe. This seals and separates from the exhaust device. The vacuum in the airtight container is maintained by the getter film. In addition, by using the non-evaporable getter, it is possible to function as an exhaust device for the hermetically sealed container after sealing, so that the discharge gas and the like at the time of driving can be sucked and exhausted, and the vacuum in the hermetic container can be maintained.

[0009]

However, conventionally,
The following problems occur in the vacuum process for maintaining the vacuum by the evaporable getter or the non-evaporable getter as described above.

When evaporating Ba, for example, as an evaporable getter, it is necessary to locally heat it to a temperature close to 1000 ° C. Also, when activating the non-evaporable getter, 75%
It is necessary to heat to 0-900 ° C.

In a flat panel image display using a field emission type electron source, a local temperature when heating an evaporable getter or a non-evaporable getter may cause a rapid temperature gradient in a part of an airtight container. Yes. In particular, the glass plate constituting the panel of the airtight container was stressed, and cracks were sometimes generated. In particular, cracks often occurred at a portion where a hole was made to connect an exhaust pipe, or at a portion where an adhesive was attached to a glass plate.

When activating the getter, the getter is heated from 350 ° C. to 1200 ° C. For this reason, a sudden temperature difference may be caused to cause damage to a material having poor thermal conductivity, such as a glass member constituting an airtight container. For example, when a temperature difference of 50 ° C. or more per mm is generated and the fixing is performed so that thermal expansion cannot be performed, cracks may occur in the glass or the adhesive. Further, when the getter portion is heated, if cold air or the like comes into contact with the outside of the airtight container, there is a problem that a larger temperature difference is generated and a crack or the like may be generated in the glass.

It is an object of the present invention to provide a method of manufacturing an image forming apparatus having a high yield without generating cracks when the getter is heated as described above.

[0014]

According to the present invention, there is provided an image forming apparatus having an electron-emitting device, a phosphor (image forming member), an exhaust pipe, a non-evaporable getter and / or an airtight container having a non-evaporable getter. The method comprises activating the getter:
It is characterized by installing a cover.

Further, the present invention is characterized in that a window through which the getter can be seen is provided.

The same effect can be obtained even when the cover comes into contact with the airtight container.

In particular, the present invention is characterized in that the cover in contact with the airtight container is formed of a material having a thermal conductivity of 1 W / m / k or more.

Further, the present invention has a feature that a plurality of getters can be simultaneously activated by providing a cover.

According to the method of manufacturing an image forming apparatus of the present invention, an image forming apparatus having an airtight container having an electron-emitting device, a phosphor, an exhaust pipe, and a non-evaporable getter or / and a non-evaporable getter is provided. In the manufacturing method, when activating the getter, by installing a cover in an airtight container,
It is possible to prevent external cold air from directly contacting the airtight container and prevent a temperature difference of 50 ° C. or more per 1 mm from the material of the airtight container. Therefore, the occurrence of cracks and the like can be prevented without causing a sharp temperature difference that may lead to breakage of the glass, the adhesive, and the like.

Further, by providing a cover having good thermal conductivity so as to be in contact with the airtight container, even if the temperature of the surface of the airtight container rises, the heat is quickly diffused around, so that a local The occurrence of a temperature difference can be prevented.
For this reason, the occurrence of cracks and the like can be prevented without generating a sudden temperature difference that may lead to breakage of the glass, the adhesive, and the like.

Further, by providing a light-transmitting window in a part or the whole of the cover portion above the getter, it is possible to quickly detect an abnormality or the like when heating the getter,
This will contribute to improving the yield.

[0022]

Embodiments of the present invention will be described. As an example, a non-evaporable getter activation step will be described below. As an example of the present invention, a cover 4 configured as shown in FIG. In the figure, 1 is a non-evaporable getter, 4 is a cover, 5 is a transparent window, 25 is a rear plate, 26 is a support frame, and 27 is a face plate. In this embodiment, the outside of the airtight container 7 was covered with the cover 4 made of Al so that cold outside air did not directly touch the airtight container. Also, a transparent acrylic window 5 was provided so that the heating state of the non-evaporable getter 1 could be seen. Here, cover 4
Is only required to be able to block the outside air, and may be made of metal, plastic, ceramics or the like. In addition, window 5
It goes without saying that any material may be used as long as it transmits light. In the case where heating is performed using a high frequency from the outside, a glass material that transmits the high frequency is desirable. In addition, it is desirable to reduce the number of openings in the peripheral portion as much as possible.

As another example of using a cover, a cover 54 having the structure shown in FIG. 5 may be installed so as to be close to the airtight container 7. 54 is a cover, and 55 is a window. The window 55 functions as a window for checking whether or not the heating state of the getter 1 in the airtight container is abnormal.

Here, the cover can be made of any material that can block the outside air.
/ M / k or more is preferably used. When a glass plate is used, it may be used as it is, but when a material such as an opaque heat conductive sheet (silicone rubber) is used, it is desirable to make a hole in the upper part of the getter and use a transparent window material. In the case where the evaporable getter or the like is activated by heating at a high frequency, it is desirable to use a material that is transparent and transmits a high frequency.

Further, by using the cover as described above, it is possible to activate a plurality of or large-area getters at a time.

[0026]

[Embodiment 1] In the first embodiment of the present invention, in which an image forming apparatus having the structure shown in FIG. 2 is formed, a surface conduction electron-emitting device 22 is provided on a rear plate 25. Are formed N × M. In this embodiment, N
Was 240 and M was 720.

The 240 × 720 surface conduction electron-emitting devices are arranged in a simple matrix by 720 row-direction wirings 23 (also called lower wirings) and 240 column-direction wirings 24 (also called upper wirings). I have.

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.
3A is a plan view, and FIG. 3B is a cross-sectional view. In FIG. 3, 31 is a substrate, 32 and 33 are device electrodes, 34 is a conductive thin film, and 35 is an electron emitting portion.

While the airtight container is evacuated to a vacuum through the exhaust pipe 11, the conductive thin film 3 is passed through the device electrodes 32 and 33.
By subjecting the conductive thin film 4 to a forming treatment, the conductive thin film is locally destroyed, deformed, or altered to form an electron emitting portion 35 in an electrically high-resistance state. When the pressure becomes 10 ⁻³ Pa or less, benzonitrile is introduced as an activating gas into the airtight container through the exhaust pipe 11 by about 0.1 Pa, and an activation step for significantly improving the emission current is performed. A voltage is applied to the device electrodes 32 and 33 thus formed, and a current flows through the device, thereby activating the above-described electron-emitting portion 35.

On the lower surface of the face plate 27,
A phosphor (image forming member) 28 is formed. 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 a portion of the fluorescent film 28.

A metal back 29 known in the field of CRTs is provided on the surface of the fluorescent film 28 on the rear plate side. The purpose of providing the metal back 29 is to improve the light efficiency by mirror-reflecting a part of the light emitted from the fluorescent film 28, to protect the fluorescent film 28 from negative ion collision, and to reduce the electron beam acceleration voltage. It is used as an electrode for application, or acts as a conductive path for the excited electrons of the fluorescent film 28. Metal back 29 is fluorescent film 2
8 was formed on the face plate substrate 27, the fluorescent film 28 was smoothed, and Al was formed thereon by vacuum evaporation. When a low-voltage fluorescent film is used as the fluorescent film 28, the metal back 29 is not used.

Although not used in this embodiment, for the purpose of applying an accelerating voltage and improving the conductivity of the fluorescent film, for example, an I.D.
A transparent conductive film such as TO may be provided.

Dox1 to Doxm and Doy1 to Dox1
Doyn and Hv are electric connection terminals of an airtight container provided for electrically connecting the display panel to an electric circuit (not shown). Dox1 to Doxm are connected to the row wiring 23 of the multi-electron beam source and Doy1 to Doyn.
Is electrically connected to the column direction wiring 24 of the multi-electron beam source, and Hv is electrically connected to the metal back 29 of the face plate.

The structure of the image forming apparatus to which the manufacturing method of the present invention is applied has been described.

Next, a method for manufacturing the image forming apparatus of the present invention will be described with reference to FIG.

(Preparation of Rear Plate) (R-1) The blue plate glass was washed, and the lower wiring 23 was formed by screen printing on the rear plate on which a silicon oxide film was formed by a sputtering method. Next, the lower wiring 23 and the upper wiring 24
An interlayer insulating film is formed therebetween. Further, the upper wiring 24 was formed. Next, device electrodes 32 and 33 connected to the lower wiring 23 and the upper wiring 24 were formed.

(R-2) Next, a conductive thin film 34 made of PdO was formed by a sputtering method and then patterned to obtain a desired form.

(R-3) Frit glass for fixing the support frame was formed at a desired position by printing.

Through the above steps, a rear plate on which a surface conduction type emission device having a simple matrix wiring, an adhesive for a support frame, and the like were formed was prepared.

(Preparation of Face Plate) (F-1) A phosphor and a black conductor were formed on a blue plate glass substrate 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) Frit glass for fixing the support frame was formed at a desired position by a printing method.

Through the above steps, a phosphor having three primary color phosphors arranged in stripes, an adhesive for a support frame, and the like were formed on the face plate.

(Preparation of Airtight Container by Sealing Rear Plate and Face Plate) (FR-1) The rear plate is held on a hot plate on an X, Y, and θ adjustment stage, and sealed while performing face plate alignment. The temperature of the rear plate and the face plate is raised to the arrival temperature. The sealing temperature is determined by the frit glass, but in this embodiment, the sealing temperature is 4
It was 10 ° C. When the temperature is raised to the sealing temperature, X,
The support frame is brought into contact with the rear plate and face plate while adjusting the position using the Y and θ adjustment stages.
After holding for 10 minutes while applying pressure, the temperature was lowered at 3 ° C./min. When the temperature was lowered by 100 ° C. from the sealing temperature, the alignment was stopped, the stage was freed, and the temperature was lowered to room temperature.

(Preparation of Electron-Emitting Element by Vacuum Process) (S-1) The exhaust pipes 11 and 12 on the face plate of the airtight container prepared as described above are connected to a vacuum exhaust device, and the inside of the airtight container is evacuated. Evacuate to vacuum.

(S-2) The pressure in the airtight container is 0.1 P
a, the external terminals Dox1 to Doxm and D
A voltage as shown in FIG. 4A was applied to the electron-emitting device through oy1 to Doyn, and a forming process was performed on the conductive thin film 34.

(S-3) Subsequently, when the pressure in the hermetic container becomes 1 × 10 ⁻³ Pa or less, 1 Pa of benzonitrile as an activating gas is introduced into the hermetic container through the exhaust pipe 11 and a terminal outside the container is provided. Dox1-Doxms and Doy1-D
A voltage as shown in FIG. 4B was applied to the electron-emitting device through Oyn to perform an activation process.

(Degassing Step in Airtight Container) The degassing step in the airtight container will be described below.

(D-1) After the activation gas has been sufficiently exhausted, the airtight container is subjected to baking degassing. The baking temperature was 300 ° C. The heating rate was 2 ° C. per minute.

(D-3) At the stage where the temperature of the airtight container was maintained at 300 ° C. for 10 hours, a part of the exhaust pipe 11 was heated and melted, and sealing was performed.

(D-4) After the sealing is completed, the temperature of the airtight container is lowered at a rate of 2 ° C. per minute and cooled to room temperature.

(Non-evaporable getter activation step) The non-evaporable getter activation step will be described below. In the first embodiment of the present invention, a cover having the structure shown in FIG. 1 was installed so as to cover the airtight container. In the figure, 1 is a non-evaporable getter, 4 is a cover,
5 is a transparent window. In this embodiment, the outside of the airtight container is covered with an Al cover 4 so that cold outside air does not directly touch the airtight container. Also, a transparent acrylic window 5 was provided so that the heating state of the non-evaporable getter 1 could be seen.

Under these circumstances, the non-evaporable getter 1
A current was supplied from the current introduction terminals 2 and 3 shown in FIG. 2 to heat the non-evaporable getter 1 at 600 ° C. for 10 minutes and then at 900 ° C. for 10 minutes. No cracks or the like were found in any of the components of the airtight container.

[Embodiment 2] This embodiment is also an example of an image forming apparatus using a surface conduction electron-emitting device. See FIGS. 2, 3 and 4 for the image forming apparatus. The method of manufacturing the image forming apparatus was the same as in Example 1 up to (the degassing step in the airtight container).

(Non-evaporable getter activation step) Next, FIG.
The cover having the structure shown in FIG. In the present embodiment, reference numeral 54 denotes a cover made of Al.
5 is a glass plate. The glass plate 55 functions as a window for checking whether the heating state of the non-evaporable getter 1 in the airtight container is abnormal.

Even with the cover having such a structure, even if the non-evaporable getter 1 was heated at 1000 ° C. for 10 minutes, no crack was observed in the airtight container.

[Embodiment 3] An image forming apparatus was manufactured in the same manner as in Embodiment 2 in Embodiment 3 of the present invention. In this example, the heat conductive sheet was placed so as to be in contact with the airtight container. Further, a hole was made on the non-evaporable getter, and a transparent sapphire glass was placed thereon.

Even with the cover having such a configuration, even if the non-evaporable getter 1 was heated at 900 ° C. for 10 minutes, no crack was observed in the airtight container.

Embodiment 4 An image forming apparatus was manufactured in the same manner as in Embodiment 2 except that an evaporable getter was used instead of a non-evaporable getter in the fourth embodiment of the present invention.

In this example, the glass plate was placed in contact with the airtight container. Evaporable getter is B on Ni ring
a is on board, 330kHz 200
Ba was evaporated by heating with W.

At this time, in the case of one ring-shaped evaporable getter, activation is completed in about 10 seconds.

The Ni ring was heated to 1200 ° C.
No cracks were observed in the airtight container.

[Embodiment 5] In the fifth embodiment of the present invention, the non-evaporable getter 1 and the evaporable getter 6 are arranged and used as shown in FIG. An image forming apparatus was manufactured in the same manner as described above.

In this embodiment, when activating the evaporable getter, the glass plate was placed in contact with the airtight container. In the evaporating type, Ba is placed on a ring made of Ni, and Ba was evaporated by heating at a frequency of 330 kHz and 200 W with a high frequency heating device.

Using the cover used in Example 1, 3
At the same time, three non-evaporable getters 1
Even after heating for 10 minutes, no cracks or the like were observed in the airtight container.

[0065]

As described above, according to the present invention,
The non-evaporable getter can be heated at a high temperature without causing cracks or the like in the airtight container.

Further, since the non-evaporable getter can be heated at a high temperature, the adsorption characteristics of the non-evaporable getter are improved several times, so that the deteriorated gas can be removed more quickly.

When the evaporable getter is evaporated by using the cover, it can be activated with high power in a short time.

Further, since a large number of getters can be activated simultaneously, the throughput is also improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a cover according to a first embodiment.

FIG. 2 is a schematic perspective view of an image forming apparatus using a surface conduction electron-emitting device.

FIG. 3 is a schematic view showing a configuration of a surface conduction electron-emitting device.

FIG. 4 is a voltage profile of forming and activation.

FIG. 5 is a schematic sectional view showing a cover according to a second embodiment.

FIG. 6 is a getter arrangement diagram of a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-evaporable getter 2,3 Current introduction terminal 4,54 Cover 5,55 Window 6 Evaporable getter 7 Airtight container 22 Surface conduction electron-emitting device 23 Row-direction wiring (lower wiring) 24 Column-direction wiring (upper wiring) 25 Rear plate 26 Support frame 27 Face plate 32, 33 Device electrode 34 Conductive thin film 35 Electron emission part

Claims (7)

[Claims] 1. A method of manufacturing an image forming apparatus comprising an air-tight container having an electron-emitting device, an image forming member, an exhaust pipe, a non-evaporable getter and / or an evaporable getter, wherein, when the getter is activated, A method for manufacturing an image forming apparatus, comprising: providing a cover for shielding the airtight container from outside air. 2. The method according to claim 1, wherein a window through which the getter can be seen is provided in the cover. 3. The method according to claim 1, wherein the airtight container and the cover are in contact with each other. 4. The method according to claim 3, wherein the cover in contact with the airtight container is formed of a material having a thermal conductivity of 1 W / m / k or more. 5. The method of manufacturing an image forming apparatus according to claim 1, wherein a plurality of getters are activated simultaneously. 6. The method for manufacturing an image forming apparatus according to claim 3, wherein a heat conductive sheet is provided so as to be in contact with said airtight container. 7. The method according to claim 3, wherein a glass plate is provided so as to be in contact with the airtight container.