JP2000251711A - Sealing method of image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing method of an image display device capable of reducing a component pressure of an emitted gas from respective members, retaining an area of an electron radiation source to a relatively low temperature, preventing an oxidation deterioration of a getter material and imparting no thermal damage to the respective member such as an electron-emitting element. SOLUTION: An assembly 19 in which a frame member 9 is assembled to a face plate 1 is retained by an upper hot plate 221 and a rear plate 8 is placed on a lower hot plate 228. A pressure is applied from the above and the below. An inert gas is distributed to an internal space S and the respective constitution members are heated. This heating keeps them to a lower temperature than a temperature at which a frit glass 22 of a sealing member is softened. A laser beam L is scan-radiated to a joining portion by a laser device 23 and is absorbed by the frit glass 22 at the portion and then heating is locally carried out to a sealing temperature. The frit glass is molten and the frame member 9 and the rear plate 8 are fused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for an image display device in which an electron emission source and an image forming member (phosphor) are arranged opposite to each other in a flat vacuum vessel and an image is formed by irradiation with an electron beam. More particularly, the present invention relates to a sealing method of an image display device in which a frame member is provided in a gap between a face plate and a rear plate and sealed.

[0002]

2. Description of the Related Art As a display device, a thin flat type image display device has been actively developed because of its excellent installation space utilization and light weight. Among them, a cold cathode type electron-emitting device and a plasma light emission principle are used. The self-luminous image display device used has attracted attention because it provides a bright image and has a wide viewing angle.

A cold-cathode-type electron-emitting device emits so-called cold electrons from a cold cathode.
ld Emission (FE) type, metal / insulating layer / metal (Metal Insulator Metal: M)
IM) type and surface conduction type.

The FE type is disclosed, for example, in W. P. Dyke &
W. W. Dolan, "Fielddemissio
n ", Advance in Electron P
physics, 8, 89 (1956) or C.I. A.
Spindt, “PHYSICAL Property
es of thin-film field emi
session cathodes with mollyb
denium cones ", J. Appl. Phys.
s. , 47, 5248 (1976).

The MIM type is described in, for example, C.I. A. Mea
d, “Operation of Tunnel-Em
issue Devices ", J. Apply. P.
hys. , 32, 646 (1961).

A surface conduction electron-emitting device is described in, for example, M.
I. Elinson, Radio Eng. Elect
ron Phys. , 10, 1290, (1965) and the like are known.

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current in parallel to a small-area thin film surface formed on a substrate. As the surface conduction electron-emitting device, the above-described Sinson et al.
One using an nO ₂ thin film, one using an Au thin film [G. D
ittmer: "Thin Solid Film
s ", 9,317 (1972)] , In 2 O 3 / SnO
₂ 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)].

In a flat-panel image display device, a large number of the above-described electron-emitting devices are arranged to constitute an electron emission source, and a phosphor is excited by an electron beam emitted by the electron emission source to display light. Is going. In other words, on the rear plate,
A large number of electron-emitting devices are arranged to form an electron emission source, a face plate is provided with a phosphor film layer, and a frame member is set in a gap that separates both plates in parallel and sealed with frit glass. Thus, a main body to be a vacuum container is formed.

The main body (vacuum container) is provided with a getter material for adsorbing the released gas in order to maintain a vacuum, and further has a spacer for holding the gap between the two plates withstanding the atmospheric pressure. In some cases, a configuration is adopted.

In any case, both plates forming a vacuum container,
The frame member is formed from a glass member, and their sealing is performed by applying or placing a frit glass serving as a sealing member between joining portions of the glass members, and placing the frit glass in a heating furnace such as an electric furnace, or with a heating heater. The assembly (vacuum container) is heated to a temperature at which the sealing member is softened by placing it on a hot plate or sandwiching the hot plate from above and below, and the joints are fused by the melted sealing member. A sealing method is adopted.

Further, there is an evaporable getter as the getter material,
If the heating temperature at the time of sealing is too high, the evaporable getter is oxidized, and various measures have been proposed to prevent it. For example, Japanese Patent Application Laid-Open No. 7-037506 discloses a technique in which the interior of a vacuum vessel is replaced with nitrogen gas at the time of sealing, thereby preventing oxidation of an evaporable getter.

[0012]

However, in the sealing technique disclosed in the above publication, the getter material is protected by replacing the inside of the vacuum vessel with nitrogen gas. In order to heat to high temperature, gas such as water and carbon monoxide is released from the glass member forming the vacuum container or the frit glass of the sealing member, and the atmosphere in the container increases the partial pressure of each gas, The region of the array of electron-emitting devices (electron radiation source) is also exposed to high temperatures, which causes a problem that the conductive thin film of the electron-emitting device causes aggregation or the like. This causes a problem in that a voltage cannot be applied to a crack portion serving as an electron-emitting portion because a voltage drop occurs at the aggregated portion during the activation process of the electron-emitting device. And the device characteristics are degraded, resulting in deterioration of the yield.

Further, in order to heat to a high temperature at the time of sealing,
There is a problem that each member constituting the inside of the vacuum vessel is thermally damaged. In particular, if the getter material is damaged by heating, an image cannot be displayed brightly and its life is shortened.

The present invention has been made in view of such a conventional problem, and when forming a flat vacuum vessel, it is possible to reduce the partial pressure of the gas emitted from each member and to obtain an electron emission source. It is an object of the present invention to provide a method of sealing an image display device, which can maintain the region of the image display device at a relatively low temperature, can prevent oxidative deterioration of the getter material, and do not thermally damage each member such as an electron-emitting device. I do.

[0015]

According to a first aspect of the present invention, there is provided a method for sealing an image display device, comprising the steps of: providing a frame in a gap between a first substrate and a second substrate separated in parallel; A method for sealing an image display device including an electron radiation source and an image forming member facing each other in a vacuum vessel sealed by providing a member, wherein the first substrate, the second substrate, and the frame member are attached to each other. A sealing member is disposed at a joint portion and temporarily assembled, and when the assembly is heated for sealing, the heating temperature is kept lower than a temperature at which the sealing member softens, and the assembly is performed. An inert gas is allowed to flow through the internal space of the body, and thereafter, the sealing member at the joint is locally heated and sealed by local heating means.

According to a second aspect of the present invention, in the method for sealing an image display device, the local heating means is directly heated by the optical heating means such as a laser to the sealing member at the joint. And direct heating means.

According to a third aspect of the present invention, there is provided a method for sealing an image display device, wherein the local heating means is supplied to a metal foil or a metal film provided in the vicinity of the joining portion by applying a current to the portion. Direct heating means for directly applying heat to the sealing member.

Further, in the sealing method for an image display device according to a fourth aspect, the local heating means is energized to an electric heater provided at a corresponding portion of a holding member for holding the assembly from above and below to temporarily assemble the assembly. Thus, an indirect heating means for indirectly applying heat to the sealing member at the joint portion via the first substrate or the second substrate.

According to a fifth aspect of the present invention, the sealing member is made of frit glass.

According to the above method, the first substrate, the second substrate, and the frame member are temporarily assembled by disposing a sealing member at a joint portion between the first substrate, the second substrate, and the frame member. When the body is heated for sealing, the heating temperature is kept lower than the temperature at which the sealing member softens, so that the members constituting the interior are not exposed to high temperatures. At this time, an inert gas is circulated in the internal space of the assembly, so that preheating for assisting sealing is performed in an inert gas atmosphere, and gas released from each member is discharged to the outside.

Thereafter, the sealing member at the joint is locally heated and sealed by the local heating means, so that only the sealing member can be melted, and the sealing can be performed reliably.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for sealing an image display device according to the present invention will be described below with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a partially exploded perspective view showing an image display device manufactured by applying the sealing method of the present invention, and FIG.
(A), (b) is a plan view (a) and a cross-sectional view (b) of the surface conduction electron-emitting device constituting the electron emission source shown in FIG.
It is. FIG. 3 is a side view showing the first embodiment of the present invention and illustrating a sealing step of the image display device of FIG.

In this image display device, a large number of surface conduction electron-emitting devices 41 are arranged to constitute an electron emission source.
The fluorescent film 46 is excited by the electron beam emitted from the electron emission source to perform light emission display. That is, the rear plate 8
On the upper surface, a large number of electron-emitting devices 41 are arranged to constitute an electron emission source.
Is formed, and a frame member 9 is set in a gap which separates both plates 8 and 1 in parallel, and an envelope 20 which becomes a vacuum container is formed by sealing with frit glass 21 and 22.

The rear plate 8 is provided with an evaporable getter 10 for adsorbing the released gas to maintain a vacuum. Further, a configuration may be adopted in which a spacer is provided to hold the gap between both plates 8 and 1 withstanding the atmospheric pressure.

N × M electron-emitting devices 41 serving as electron-emitting sources are formed on the rear plate 8, and N and M are appropriately set according to the number of display pixels. And N × M
In order to drive each element,
M lower wires 43 extending in the row direction and N lower wires 43 extending in the column direction
A book upper wiring 42 is provided, and a so-called simple matrix wiring is provided. External terminals Dox1 to Doxm, Doy1 to Doyn for connecting to a drive system electric circuit (not shown) are provided at ends of the lower wiring 43 and the upper wiring 42.
Is provided.

As shown in FIG. 2, the electron-emitting device 41
An element configuration in which a conductive thin film 34 is formed between two element electrodes 32 and 33 provided on a substrate 31 (rear plate 8) is adopted. Is formed.

Forming is an energization process in which a voltage is applied to both ends (element electrodes 32, 33) of the conductive thin film 34 in a vacuum to locally destroy, deform or alter the conductive thin film 34. Thus, the electron emission portion 35 in an electrically high resistance state is formed. That is,
The electron emitting portion 35 is a crack or the like formed in a part of the conductive thin film 34. When a voltage is applied to both ends of the conductive thin film 34, electrons are emitted from the vicinity of the crack or the like.

After the sealing of the envelope 20 is completed, the activation of the electron emission section 35 is performed. This is because the pressure inside the envelope 20 is reduced to 1 × 10 ⁻³ P
a, the introduction pipe 7 is inserted into the envelope 20.
This is an energization process in which acetone is introduced at about 1 Pa as an activating gas, and a voltage pulse is applied to the device electrodes 32 and 33. The electron emission characteristics are improved by passing a current through the device.

The fluorescent film 46 formed on the lower surface of the face plate 1 is made of only a phosphor in the case of a monochrome display.
In the case of displaying a color image, phosphors of three primary colors of red, green and blue are separately painted to form pixels.

A metal back 45 is provided to cover the surface of the fluorescent film 46. This metal back 45
After the fluorescent film 46 is formed on the face plate 1,
The fluorescent film 46 is formed by a smoothing process, and Al is formed thereon by vacuum deposition, and is electrically connected to a high-voltage terminal Hv provided on the outer surface of the face plate 1. Is applied.
That is, the metal back 45 plays a role of mirror-reflecting a part of the light emitted from the fluorescent film 46 to improve the luminance efficiency and protecting the fluorescent film 46 from the collision of negative ions. Further, it functions as an anode electrode for applying an acceleration voltage of an electron beam, and also functions as a conductive path for guiding electrons that have excited the fluorescent film 46.

A transparent conductive film such as ITO may be provided between the face plate 1 and the fluorescent film 46 in order to improve the conductivity of the anode electrode to which the acceleration voltage is applied and the fluorescent film 46.

The manufacture of this image display device is performed by the following steps.

(Manufacturing Process of Rear Plate 8) (1) The lower wiring 43 is formed by screen printing on a soda lime glass (rear plate) having a silicon oxide film formed on the surface. Next, an interlayer insulating film to be an interlayer between the lower wiring 43 and the upper wiring 42 is formed, and the upper wiring 42 is further formed. Then, the device electrodes 32 and 33 are formed by being connected to the lower wiring 43 and the upper wiring 42. (2) Subsequently, a conductive thin film 34 made of PdO is formed, patterned and formed into a predetermined shape. (3) Next, the soda lime glass (rear plate) is put into a vacuum device and evacuated. When the pressure becomes 0.1 Pa or less, a voltage is applied to each electron-emitting device 41 through the external terminals Dox1 to Doxm and Doy1 to Doyn. Apply the conductive thin film 34
Forming is performed. (4) And on the blue plate glass (rear plate)
The evaporable getter 10 is provided in a predetermined manner.

Through the above steps, an array of surface-conduction type electron-emitting devices 41 provided with a simple matrix wiring, that is, an electron emission source, is formed on the blue plate glass, and the rear plate 8 can be manufactured.

(Manufacturing process of the face plate 1) (1) A film layer 46 of a phosphor and a black conductor are formed on a blue plate glass, and the surface of the phosphor film 46 is subjected to a smoothness treatment. Then, a metal back 45 is formed. (2) Then, a frit glass 21 for fixing the frame member 9 is formed on the periphery of the soda lime glass in a predetermined manner.

Through the above steps, the phosphor film 46 in which the phosphors of the three primary colors are arranged in stripes is formed on the blue plate glass, and the face plate 1 can be manufactured.

(Step of Assembling and Fixing Faceplate 1) (1) The frame member 9, the faceplate 1, the introduction pipe 7, and the exhaust pipe 71 are fixed to a fixing jig (not shown) so as to be aligned in a correct positional relationship. At this time, the frit glass 2
1 is formed at the joint between the frame member 9 and the face plate 1. (2) This is placed in an electric furnace, fired, and fixed. Thereby, the frame member 9 is assembled on the face plate 1 side, and the assembly on the face plate 1 side is completed. (3) Thereafter, the assembly is taken out of the electric furnace, and frit glass 22 as a sealing member is formed at the joint of the frame member 9 on the rear plate 8 side.

(Process of Manufacturing Enclosure 20 by Local Heating)
Here, as shown in FIG. 3, a laser device 23 is used as a local heating means to be described later, and heat is directly applied to a sealing member at a joint portion to perform sealing.

(Step-1) An assembled body 19 in which the frame member 9, the introduction pipe 7, and the exhaust pipe 71 are assembled on the face plate 1,
The rear plate 8 is placed on the lower hot plate 228 while being held by the upper hot plate 221.
At this time, the lower hot plate 228 is fixed on an adjustment stage (not shown) in advance, and can be adjusted for each of the X, Y, and θ axes.

A gas flow system is connected to the introduction pipe 7 and the exhaust pipe 71. The gas flow system is connected to an introduction gas heater 25 for heating and controlling the introduction gas and a mass flow controller 26 for controlling the flow rate on the introduction pipe 7 side, and a mass flow meter for monitoring the gas flow state on the exhaust pipe 71 side. 27
Connect. At this time, the rear plate 8 and the assembly 1
9 is appropriately adjusted by an adjustment stage, and the frame member 9 and the rear plate 8 are brought into contact with each other and pressurized.

(Step-2) Next, an inert gas is allowed to flow through the internal space S formed by bringing the frame member 9 into contact with the rear plate 8, and each component is heated to a predetermined temperature. That is, the gas flow rate is controlled to a predetermined amount by the mass flow controller 26, and the rear plate 8 and the assembly 19 are heated by the hot plates 228 and 221 from the temperature at which the frit glass 22 used for the sealing member softens (sealing temperature). Is also heated to a low temperature. In order to prevent cracks due to thermal distortion of the glass, heating for suppressing heat distribution is performed. In this heating, the flow gas is heated by the introduction gas heater 25, and the heating of the introduction gas is synchronized with the temperature control of the hot plates 228 and 221.

(Step-3) After the heating control in step-2 is equilibrated, the laser device 23 scans and irradiates the contact portion between the frame member 9 and the rear plate 8 with the laser device 23 to form the contact portion. It is absorbed by a certain frit glass 22 and locally heated to a sealing temperature.

The laser device 23 is a local heating means for performing local heating. As the laser device 23, the generated laser light L passes through the glass but is absorbed by the black or gray sealing material. Any laser having a wavelength can be used, and any laser such as a semiconductor laser, a carbon dioxide laser, and a YAG laser can be used.

Accordingly, the frit glass 22 is melted by the irradiation of the laser beam L, the frame member 9 and the rear plate 8 are fused, and an envelope 20 forming a vacuum vessel is formed.

(Step-4) After the entire periphery of the frame member 9 is scanned and irradiated with the laser beam L, the temperatures of the hot plates 228 and 221 are lowered to room temperature. At this time, the temperature of the introduced gas is also reduced synchronously.

(Step-5) When the envelope 20 has reached room temperature, the gas introduction flow is stopped. Thereby, the envelope 20 formed in the airtight container can be manufactured.

(Manufacturing Step of Electron Emitting Element 41 by Vacuum Process) (1) The introduction pipe 7 of the envelope 20 manufactured as described above is sealed, and the exhaust pipe 71 is connected to an exhaust system to perform exhaust. Then, the envelope 20 is evacuated. (2) Subsequently, when the pressure in the envelope 20 becomes 1 × 10 ⁻³ Pa or less, acetone is used as an activating gas and the exhaust pipe 71 is used.
1Pa is introduced inside through the external terminals Dox1 to Dox
A predetermined voltage is applied to m, Doy1 to Doyn to activate each electron-emitting device 41.

(Degassing Step in Envelope 20) (1) Next, the activated gas in the envelope 20 is exhausted, and when the activated gas exhaust reaches a predetermined level, heating is started together with the exhaust. Then, a baking degassing process is performed in which the temperature is set to 300 ° C. and the temperature is maintained for 10 hours. Thereafter, a part of the exhaust pipe 71 is heated and melted, and the envelope 20 is hermetically sealed.
So-called chip off.

Thus, the production is completed, and an image display device can be obtained.

By the above steps, the sealing method of the image display device according to the present embodiment is performed in such a manner that the assembly 19 of the face plate 1 and the frame member 9 and the rear plate 8 are joined to each other at the joint of the frit glass of the sealing member. When the assembly 22 is disposed and temporarily assembled, and the assembly is heated for sealing, the heating temperature is kept lower than the temperature at which the frit glass 22 softens. Not exposed. At this time, since the inert gas is circulated in the internal space S of the assembly, preheating is performed to assist the sealing in the atmosphere of the inert gas, and the gas released from each member is discharged to the outside.

Then, the frit glass 2 at the joint is
2 is locally heated and sealed by the laser device 23 of the local heating means, so that only the frit glass 22 can be melted, and the sealing can be performed reliably.

Therefore, the partial pressure of the gas emitted from each member can be reduced, and only the frit glass 22 at the joint is locally heated, so that the region of the electron emission source 18 is kept at a relatively low temperature. Therefore, each member such as the electron-emitting device 41 is not thermally damaged. Since the heating is performed in an atmosphere in which the inert gas flows, the oxidative deterioration of the evaporable getter 10 can be prevented.

As a result, damage such as agglomeration in the conductive thin film 34 of the electron-emitting device 41 can be prevented, the activation can be performed well, and the device characteristics can be stabilized and the yield can be improved.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention and is a side view for explaining a sealing step of an image display device.

In the second embodiment, as shown in FIG. 4, a heating wire 2 which generates heat by energization is used as a local heating means described later.
Using 8, heat is directly applied to the sealing member at the joint to perform sealing.

The heating wiring 28 is a metal film that generates heat when energized, and is overlapped with the frit glass 22 of the sealing member on the joint of the frame member 9 on the rear plate 8 side in the mounting and fixing step on the face plate 1 side. To be formed. Examples of the material of the heating wiring 28 include NiCr, Ti, and Ni, which have a coefficient of linear expansion close to that of a glass member, have a small thermal stress with glass, and have a high resistance that can generate a large amount of heat even at a low current. Is preferred.

(Step-1) Step-1 is the same as that of the first embodiment shown in FIG. 3 described above, and a description thereof will be omitted.

(Step-2) Step-2 is the same as that of the first embodiment shown in FIG. 3 described above, and the description thereof is omitted.

(Step-3) After the heating control in step-2 is equilibrated, the heating wire 28 formed in the contact portion between the frame member 9 and the rear plate 8 is energized, and the frit formed in that portion is also turned on. The glass 22 is heated to a predetermined temperature. That is, local heating is performed to the sealing temperature, whereby the frit glass 22 is melted, the frame member 9 and the rear plate 8 are fused, and the envelope 20 forming a vacuum vessel is formed. .

(Step-4) After the frit glass 22 is melted, the calorific value of the heating wiring 28 is gradually reduced, and the applied power is reduced to zero. After this, both hot plates 2
The temperature of 28,221 is lowered to room temperature. At this time, the temperature of the introduced gas is also reduced synchronously.

(Step-5) When the envelope 20 has reached room temperature, the gas introduction flow is stopped. Thereby, the envelope 20 formed in the airtight container can be manufactured.

In this case, the same operation and effect as those of the first embodiment can be obtained.
2 is maintained at a temperature lower than the softening temperature, so that the members constituting the interior are not exposed to the high temperature, and are preheated to assist sealing in an atmosphere in which an inert gas flows.
The gas released from each member is discharged to the outside. Since the frit glass 22 at the joint is locally heated and sealed by the heating wiring 28 of the local heating means, only the frit glass 22 can be melted, and the sealing can be reliably performed.

Therefore, the partial pressure of the gas emitted from each member can be reduced, and the region of the electron emission source 18 can be kept at a relatively low temperature, so that each member such as the electron-emitting device 41 is thermally damaged. In addition, the oxidative deterioration of the evaporable getter 10 can be prevented.

As a result, damage such as aggregation in the conductive thin film 34 of the electron-emitting device 41 can be prevented, the activation can be performed well, and the device characteristics can be stabilized and the yield can be improved.

(Third Embodiment) FIG. 5 is a side view illustrating a sealing step of an image display device according to a third embodiment of the present invention.

In the third embodiment, as shown in FIG. 5, an upper hot plate 121,
Using the local heaters 131 and 138 provided at the corresponding portions of the lower hot plate 128, heat is applied indirectly to the sealing member at the joint portion via the pressed plates 1 and 8 to perform sealing. .

The local heaters 131 and 138 are electric heaters, and are disposed in the corresponding portions of the upper hot plate 121 and the lower hot plate 128 in an embedded state.

Further, the structure of the image display device is partially changed, and a structure is adopted in which a spacer 48 is fixed on the upper wiring 42 of the rear plate 8 with an inorganic adhesive as shown in FIG. Then, the gap between the plates 1 and 8 is held to withstand the atmospheric pressure. The introduction pipe 7 and the exhaust pipe 71 are attached to the rear plate 8 side. Correspondingly, the lower hot plate 128 is provided with a hole for piping.

Further, here, instead of assembling the rear plate 9 to the face plate 1, a procedure is adopted in which the face plate 1, the frame member 9, and the rear plate 8 are simultaneously sealed.

(Step-1) The face plate 1 is held on the upper hot plate 121 and the spacer 48 is
Is mounted on the lower hot plate 128, and the frame member 9 is mounted on the rear plate 8. Note that frit glasses 21 and 22 are formed on the upper and lower two joining surfaces of the frame member 9 in a previous step. The lower hot plate 128 is fixed on an adjustment stage (not shown) in advance, and X, Y,
It is possible to adjust each axis of θ.

The introduction pipe 7 and the exhaust pipe 71 on the rear plate 8 side
Connect the gas flow system to. In the gas flow system, an introduction gas heater 2 for heating and controlling the introduction gas is provided on the introduction pipe 7 side.
5 and a mass flow controller 26 for controlling the flow rate, and a mass flow meter 27 for monitoring a gas flow state is connected to the exhaust pipe 71 side. At this time, the positioning of the rear plate 8, the frame member 9, and the face plate 1 is appropriately performed by the adjustment stage, and the three members are brought into contact with each other and pressurized.

(Step-2) Next, the face plate 1,
An inert gas is allowed to flow through an internal space S formed by bringing the three members of the frame member 9 and the rear plate 8 into contact with each other, and each component is heated to a predetermined temperature. That is, the gas flow rate is controlled to a predetermined amount by the mass flow controller 26, and the rear plate 8, the frame member 9, and the face plate 1 are heated by the hot plates 128 and 121 to a temperature at which the frit glasses 21 and 22 used for the sealing member soften. Heating is performed at a temperature lower than (sealing temperature), and heating for suppressing heat distribution is performed in order to prevent cracks due to thermal distortion of glass. Along with
The local heaters 138 and 131 also generate heat, and the heating is synchronized with the temperature control of the hot plates 128 and 121. In this heating, the flow gas is heated by the introduction gas heater 25, and the heating of the introduction gas is synchronized with the temperature control of the hot plates 128 and 121.

(Step-3) After the heating control in step-2 is equilibrated, the local heaters 138 and 131 disposed corresponding to the contact portions of the frame member 9 with the rear plate 8 and the face plate 1 are supplied. The applied power is increased, and the frit glasses 22 and 21 formed in the corresponding portions are indirectly heated to a predetermined temperature via the rear plate 8 and the face plate 1. That is, local heating is performed up to the sealing temperature, whereby the frit glasses 22 and 21 are melted, and the frame member 9 and the rear plate 8 and the face plate 1 are fused to each other to form a vacuum container. A vessel 20 is formed.

(Step-4) After the frit glasses 22 and 21 are melted, the calorific value of the local heaters 138 and 131 is gradually reduced, and the lower hot plate 128 and the upper hot plate on which the heaters 138 and 131 are disposed are gradually reduced. The temperature is reduced to the same temperature as the plate 121. After this, both hot plates 12
The temperature of 8,121 is lowered to room temperature. At this time, the temperatures of the local heaters 138 and 131 are also reduced synchronously,
Then, the temperature of the introduced gas is also reduced synchronously.

(Step-5) When the envelope 20 has reached room temperature, the gas introduction flow is stopped. Thereby, the envelope 20 formed in the airtight container can be manufactured.

In this case, the same operation and effect as those of the first embodiment can be obtained.
Since the components 1 and 22 are kept at a temperature lower than the softening temperature, the components constituting the interior are not exposed to the high temperature, and are preheated to assist the sealing in an atmosphere in which an inert gas flows, thereby releasing the components. The gas is exhausted to the outside. Then, the frit glasses 21 and 22 at the joint portion are locally heated and sealed by the local heaters 131 and 138 of the local heating means.
Only 2 can be melted and sealing can be performed reliably.

Therefore, the partial pressure of the gas emitted from each member can be reduced, and the region of the electron emission source 18 can be kept at a relatively low temperature. In addition, the oxidative deterioration of the evaporable getter 10 can be prevented.

As a result, damage such as aggregation in the conductive thin film 34 of the electron-emitting device 41 can be prevented, the activation can be performed well, and the device characteristics can be stabilized and the yield can be improved.

[0079]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for sealing an image display device according to the present invention will be described below.

Example 1 In Example 1, an image display device having the structure shown in FIG. 1 was manufactured, and a color image display device having an effective display area of 15 inches diagonally and an aspect ratio of 3: 4 was manufactured. did.

According to the first embodiment, the frame member 9, the introduction pipe 7, and the exhaust pipe 71 are provided on the rear plate 8 and the face plate 1.
After the assembly 19 was assembled, sealing by local heating was performed in an inert gas flow atmosphere by the following steps. Here, sealing was performed with the configuration shown in FIG. Ba was used for the evaporable getter 10.

(Step-1) The rear plate 8 is connected to X, Y,
Lower hot plate 2 on θ adjustment stage (not shown)
28, and the assembly 19 was held on the upper hot plate 221.

A gas flow system was connected to the introduction pipe 7 and the exhaust pipe 71. In this embodiment, the inert gas to be introduced is Ar
Gas was used. In the gas flow system, an introduction gas heater 25 for heating and controlling the introduction gas and a mass flow controller 26 for controlling the flow rate are connected to the introduction pipe 7 side, and a mass flow monitoring the gas flow state to the exhaust pipe 71 side. The meter 27 was connected. At this time, the alignment between the rear plate 8 and the assembly 19 was performed by the X, Y, and θ adjustment stages, and the frame member 9 was brought into contact with the rear plate 8 and pressed.

(Step-2) Next, Ar gas is caused to flow into the internal space S, and at this time, the flow rate is controlled by the mass flow controller 26 so as to be 5 slm.
And the rear plate 8 is heated at a temperature rise of 20 ° C./minute by the hot plates 228 and 221 on the adjustment stage.
Heated to 0 ° C. At this time, both hot plates 22
At the same time as the heating of 8,221, the flow gas was synchronously heated by the introduction gas heater 25 and controlled to 300 ° C.

(Step-3) The heating control in step-2 is 300
After equilibration to ° C., the laser device 23 scan-irradiates the laser beam L, absorbs the laser beam L into the frit glass 22, and locally heats it to the sealing temperature. In this example, a frit glass having a melting temperature of 410 ° C. was used using a YAG laser. As a result, the envelope 20 forming the vacuum vessel could be sealed.

(Step-4) After irradiating the entire surface of the frame member 9 with the laser beam L for scanning, the temperatures of the hot plates 228 and 221 were lowered to room temperature at a temperature drop of 20 ° C. per minute. At this time, the temperature of the introduced gas was also reduced synchronously.

(Step-5) When the envelope 20 reached room temperature, the gas introduction flow was stopped.

The envelope 20 was manufactured by the above steps.

Thereafter, the element was activated using acetone in accordance with the first embodiment. Then, a degassing baking process was performed at 300 ° C. for 10 hours, and after the temperature was lowered to room temperature, the evaporable getter 10 was externally flashed by high-frequency heating to form a Ba deposited film.

It was confirmed that the envelope 20 had sufficient airtightness and was able to seal securely. Then, it was confirmed that image display could be performed well.

Embodiment 2 In Embodiment 2, an image display device having the structure shown in FIG. 1 is manufactured, and a color image display device having an effective display area of 3 inches diagonally and an aspect ratio of 3: 4 is manufactured. did.

According to the first embodiment, the frame member 9, the introduction pipe 7, and the exhaust pipe 71 are mounted on the rear plate 8 and the face plate 1.
After the assembly 19 was assembled, sealing by local heating was performed in an inert gas flow atmosphere by the following steps. Here, sealing was performed with the configuration shown in FIG. Ba was used for the evaporable getter 10.

(Step-1) The rear plate 8 is connected to X, Y,
Lower hot plate 2 on θ adjustment stage (not shown)
28, and the assembly 19 was held on the upper hot plate 221.

A gas flow system was connected to the introduction pipe 7 and the exhaust pipe 71. In this embodiment, N _{2 is used} as the inert gas to be introduced.
Gas was used. In the gas flow system, an introduction gas heater 25 for heating and controlling the introduction gas and a mass flow controller 26 for controlling the flow rate are connected to the introduction pipe 7 side, and a mass flow monitoring the gas flow state to the exhaust pipe 71 side. The meter 27 was connected. At this time, the alignment between the rear plate 8 and the assembly 19 was performed by the X, Y, and θ adjustment stages, and the frame member 9 was brought into contact with the rear plate 8 and pressed.

(Step-2) Next, N ₂ gas is caused to flow into the internal space S, and at this time, the flow rate is controlled by the mass flow controller 26 so as to be 1 slm.
And the rear plate 8 is heated at a temperature rise of 20 ° C./minute by the hot plates 228 and 221 on the adjustment stage.
Heated to 0 ° C. At this time, both hot plates 22
At the same time as the heating of 8,221, the flow gas was synchronously heated by the introduction gas heater 25 and controlled to 300 ° C.

(Step-3) The heating control in step-2 is 300
After the temperature was equilibrated to ° C., a current was supplied from a terminal portion (not shown) of the heating wiring 28 to locally heat the frit glass 22 to 450 ° C. In this example, frit glass having a melting temperature of 450 ° C. was used. Thereby, the envelope 2 forming a vacuum container
0 could be sealed.

(Step-4) After the frit glass 22 was melted, the calorific value of the heating wiring 28 was gradually reduced, and held at a temperature of 410 ° C. for 10 minutes to remove distortion. Thereafter, the electric power supplied to the heating wiring 28 was reduced to zero. Then, the temperature of both hot plates 228 and 221 was lowered to room temperature at a temperature drop of 20 ° C. per minute. At this time, the temperature of the introduced gas was also reduced synchronously.

(Step-5) When the envelope 20 reached room temperature, the gas introduction flow was stopped.

The envelope 20 was manufactured by the above steps.

Thereafter, the device was activated using acetone, according to the first embodiment. Then, a degassing baking process was performed at 300 ° C. for 10 hours, and after the temperature was lowered to room temperature, the evaporable getter 10 was externally flashed by high-frequency heating to form a Ba deposited film.

It was confirmed that the envelope 20 had sufficient airtightness and was able to seal securely. Then, it was confirmed that image display could be performed well.

Example 3 In Example 3, an image display device having the structure shown in FIG. 6 was manufactured according to the third embodiment, and the gap between the plates 1 and 8 was held to withstand the atmospheric pressure. The effective display area is set to a diagonal of 10
A color image display device having an inch and an aspect ratio of 3: 4 was manufactured.

After manufacturing the rear plate 8 according to the first embodiment, as shown in FIG. 6, a spacer 48 was fixed on the upper wiring 42 of the rear plate 8 with an inorganic adhesive. Then, sealing by local heating was performed in an atmosphere of an inert gas flow by the following steps. Here, sealing was performed with the configuration shown in FIG. Ba was used for the evaporable getter 10.

(Step-1) The rear plate 8 is connected to X, Y,
Lower hot plate 1 on θ adjustment stage (not shown)
28, the frame member 9 is placed on the rear plate 8, and the face plate 1 is
Was held. On the upper and lower two joining surfaces of the frame member 9,
Frit glasses 21 and 22 are formed in the previous step.

A gas flow system was connected to the introduction pipe 7 and the exhaust pipe 71. In this embodiment, the inert gas to be introduced is Ar
Gas was used. In the gas flow system, an introduction gas heater 25 for heating and controlling the introduction gas and a mass flow controller 26 for controlling the flow rate are connected to the introduction pipe 7 side, and a mass flow monitoring the gas flow state to the exhaust pipe 71 side. The meter 27 was connected. At this time, the positions of the rear plate 8, the frame member 9, and the face plate 1 are aligned with X,
The adjustment was performed using Y and θ adjustment stages, and the three members were brought into contact with each other and pressed.

(Step-2) Next, Ar gas is caused to flow into the internal space S, and at this time, the flow rate is controlled by the mass flow controller 26 to be 2 slm, and the face plate 1, the frame member 9, and the rear plate 8 are 350 ° C at a temperature rise of 20 ° C per minute by both hot plates 121 and 128
Until heated. In addition, the local heaters 131 and 138
Was also synchronized and heated to 350 ° C. At the same time as the heating of the hot plates 121 and 128, the flow gas is heated by the introduction gas heater 25 in synchronization with the heating of the hot plates 121 and 128.
Controlled to 0 ° C.

(Step-3) The heating control in the step-2 is 350
After equilibration to ° C., the electric power applied to the local heaters 131 and 138 is increased so that the frit glass 21 and 22
Heated locally to ° C. In this embodiment, the melting temperature is 45.
Frit glass at 0 ° C. was used. As a result, the envelope 20 forming a vacuum vessel could be sealed.

(Step-4) After the frit glasses 21 and 22 are melted, the calorific value of the local heaters 131 and 138 is gradually reduced, and the strain is removed by holding the temperature at 410 ° C. for 10 minutes. went. Thereafter, the temperatures of the local heaters 131 and 138 are increased by the two hot plates 121 and 138.
The temperature was lowered to the same as 128. Then, both the hot plates 121 and 128 and the local heaters 131 and 138
Was lowered to room temperature in synchronism with a temperature drop of 20 ° C. per minute. At this time, the temperature of the introduced gas was also reduced synchronously.

(Step-5) When the envelope 20 reached room temperature, the gas introduction flow was stopped.

The envelope 20 was manufactured through the above steps.

Thereafter, according to the first embodiment, the device was activated using acetone. Then, a degassing baking process was performed at 300 ° C. for 10 hours, and after the temperature was lowered to room temperature, the evaporable getter 10 was externally flashed by high-frequency heating to form a Ba deposited film.

It was confirmed that the envelope 20 had sufficient airtightness and was able to seal securely. Then, it was confirmed that image display could be performed well.

[0113]

As described above, the sealing method of the image display device according to the present invention has the following excellent effects.

According to the first aspect of the present invention, the first substrate, the second substrate, and the frame member are temporarily assembled by disposing a sealing member at a joint portion between the first substrate, the second substrate, and the frame member. Therefore, when heating, the heating temperature is kept lower than the temperature at which the sealing member softens, so that each member constituting the interior is not exposed to high temperature. At this time, an inert gas is circulated in the internal space of the assembly, so that preheating for assisting sealing is performed in an inert gas atmosphere, and gas released from each member is discharged to the outside.

Thereafter, the sealing member at the joint is locally heated and sealed by the local heating means, so that only the sealing member can be melted and the sealing can be performed reliably.

Therefore, the partial pressure of the gas released from each member can be reduced, and only the sealing member at the joint is locally heated, so that the region of the electron emission source is kept at a relatively low temperature. And does not thermally damage each member such as the electron-emitting device. Further, since the heating is performed in an atmosphere in which the inert gas flows, the oxidative deterioration of the getter material can be prevented.

As a result, damage such as aggregation in the conductive thin film of the electron-emitting device can be prevented, the activation can be performed well, and the device characteristics can be stabilized and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an image display device manufactured by applying a sealing method of the present invention.

2A is a plan view of a surface conduction electron-emitting device constituting the electron emission source shown in FIG. 1, and FIG. 2B is a cross-sectional view thereof.

FIG. 3 is a side view illustrating the first embodiment of the present invention and illustrating a sealing step of the image display device.

FIG. 4 is a side view illustrating a second embodiment of the present invention and illustrating a sealing step of the image display device.

FIG. 5 is a side view illustrating a sealing step of the image display device according to the third embodiment of the present invention.

FIG. 6 is a sectional view showing a rear plate of the image display device of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 face plate (first substrate or second substrate) 7 introduction tube 8 rear plate (second substrate or first substrate) 9 frame member 10 evaporable getter 18 electron radiation source 19 assembly 20 envelope (vacuum container) 21 , 22 frit glass (sealing member) 23 laser device (local heating means) 25 introduction gas heater 26 mass flow controller 27 mass flow meter 28 heating wiring (local heating means) 31 substrate 32, 33 element electrode 34 conductive thin film 35 electron emission Part 41 Electron emission element 42 Upper wiring 43 Lower wiring 45 Metal back 46 Fluorescent film (image forming member) 48 Spacer 71 Exhaust pipe 121, 221 Upper hot plate 128, 228 Lower hot plate 131, 138 Local heater (local heater) S Internal space L Laser beam

Claims (5)

[Claims] 1. An image display apparatus comprising an electron emission source and an image forming member opposed to each other in a vacuum container sealed by providing a frame member in a gap between a first substrate and a second substrate which are separated in parallel. In the method, the first substrate, the second substrate and the frame member are temporarily assembled by arranging a sealing member at a joint portion of each other, when heating the assembly for sealing, While maintaining the heating temperature at a temperature lower than the temperature at which the sealing member softens, an inert gas is allowed to flow through the internal space of the assembly, and thereafter, the sealing member at the joint is locally heated. A method of sealing the image display device, wherein the sealing is performed by locally heating the device. 2. The method according to claim 1, wherein the local heating means is a direct heating means for directly applying heat to the sealing member at the joint by an optical heating means such as a laser. 3. The method for sealing an image display device according to item 1. 3. A direct heating means for applying heat to a metal foil or a metal film provided in the vicinity of the joint portion to directly apply heat to the sealing member at the joint portion. The method for sealing an image display device according to claim 1, wherein: 4. The local heating means is supplied to an electric heater provided at a corresponding portion of a holding member which is pressed from above and below for temporarily assembling the assembly, and is supplied through the first substrate or the second substrate. The method according to claim 1, wherein the sealing member is an indirect heating unit that indirectly applies heat to the sealing member at the joint. 5. The method according to claim 1, wherein the sealing member is frit glass.