JP2004265601A - Image display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an image display device capable of surely jointing in a short time while stably keeping a side wall shape. <P>SOLUTION: A vacuum envelope 10 of this flat display device is provided with: a front substrate 11 and a back substrate 12 disposed oppositely to each other; and the oblong frame-like side walls 18 formed between peripheral parts of the front substrate and the back substrate. The side walls have projecting parts 18a, 18b, 18c and 18d extending outward from the respective corner parts. In manufacturing the display device, the side walls are positioned and jointed to the substrates with tension applied to respective sides of the side walls along their longitudinal directions by holding and pulling outward the respective projecting parts. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image display device having a substrate disposed oppositely, side walls disposed between the substrates, and a plurality of pixels, and a method of manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, there has been a demand for a high-definition image display device for high-definition broadcasting or a high-resolution image display device associated therewith. In order to achieve these demands, it is necessary to flatten the screen surface and increase the resolution, and at the same time, reduce the weight and thickness.
[0003]
As an image display device that satisfies the above demands, for example, a flat image display device such as a field emission display (hereinafter, referred to as an FED) has attracted attention. For example, the FED disclosed in Patent Literature 1 has a front substrate and a rear substrate that are opposed to each other at a predetermined interval, and these substrates are joined to each other at their peripheral edges via a rectangular frame-shaped side wall. By doing so, a vacuum envelope is configured. A phosphor screen is formed on the inner surface of the front substrate, and a number of electron-emitting devices are provided on the inner surface of the rear substrate as electron emission sources for exciting the phosphor to emit light.
[0004]
Further, in order to support the atmospheric pressure load applied to the rear substrate and the front substrate, a plurality of support members are disposed between these substrates. In this FED, an image is displayed by irradiating the phosphor screen with an electron beam emitted from the electron-emitting device and causing the phosphor screen to emit light.
[0005]
In such an FED, the size of the electron-emitting device is on the order of micrometers, and the distance between the front substrate and the rear substrate can be on the order of millimeters. Therefore, higher resolution, lighter weight, and thinner thickness can be achieved as compared with a cathode ray tube (CRT) used as a current television or a computer display.
[0006]
[Patent Document 1]
JP 2000-323074 A
[Problems to be solved by the invention]
In the FED having the above configuration, the side wall provided between the front substrate and the rear substrate has a very small width, and is formed to be very thin, for example, about 1 mm. Therefore, when the side wall is joined to the peripheral portion of the substrate in the process of manufacturing the FED, the side wall is difficult to hold and easily deformed, and there is a problem in that positioning takes time. At the same time, when holding the side wall, it is difficult to accurately arrange the side wall because the center of the side wall is bent or the side is twisted.
[0008]
Such a problem leads to an increase in the index time at the time of manufacturing, and causes an increase in cost. Therefore, early improvement is desired.
[0009]
The present invention has been made in view of the above points, and an object of the present invention is to provide a method of manufacturing an image display device capable of performing reliable bonding in a short time while maintaining a stable side wall shape.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an image display device according to an embodiment of the present invention includes a front substrate and a rear substrate that are opposed to each other, and a rectangular frame-shaped side wall provided between peripheral portions of the front substrate and the rear substrate. And a plurality of pixels formed in the envelope, wherein the side walls protrude outwardly from each corner along a direction parallel to the side of the side wall and can be gripped. It has a projection.
[0011]
Further, a method for manufacturing an image display device according to another aspect of the present invention includes a front substrate and a rear substrate which are arranged to face each other, and a rectangular frame-shaped side wall provided between peripheral portions of the front substrate and the rear substrate. And a method of manufacturing an image display device including a plurality of pixels formed in the envelope, wherein a rectangular frame-shaped side wall having a protrusion protruding outward from each corner is provided. Prepare, grip each of the protrusions of the side wall, pull outward, apply tension along the longitudinal direction to each side of the side wall, and apply the tension to the front substrate and the rear surface while applying the tension. It is characterized in that it is positioned and bonded to at least one of the substrates.
[0012]
According to the image display device and the method of manufacturing the image display device having the above-described configuration, the protrusion is provided at each corner of the side wall, so that the protrusion can be gripped and the side wall can be easily held. At the same time, by pulling the protruding portion outward and applying a tension in the longitudinal direction to each side of the side wall, each side of the side wall can be maintained in a flat state without distortion and twist, and in a stable shape. it can. Therefore, the side wall can be positioned and arranged accurately at a predetermined position with respect to the front substrate or the rear substrate in a short time. Therefore, it is possible to provide an image display device capable of stably joining the side walls, reducing the manufacturing cost, and displaying a stable and good image, and a method of manufacturing the same.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which an image display device of the present invention is applied to an FED will be described in detail with reference to the drawings.
[0014]
As shown in FIGS. 1 to 4, the FED includes a front substrate 11 and a rear substrate 12 each formed of a rectangular glass plate, and these substrates are arranged to face each other with a gap of 1 mm. Each substrate has a diagonal dimension of, for example, 10 inches. The size of the rear substrate 12 is larger than that of the front substrate 11, and a lead line (not shown) for inputting a video signal described later is formed on an outer peripheral portion of the rear substrate. The front substrate 11 and the rear substrate 12 are joined to each other via a rectangular frame-shaped side wall 18 to form a flat rectangular vacuum envelope 10 whose inside is maintained in a vacuum state. .
[0015]
The side wall 18 has protrusions 18a, 18b, 18c, 18d that protrude outward from the respective corners along directions parallel to the diagonal axes 40 and 42, respectively. The side wall 18 is sealed to the rear substrate 12 and the front substrate 11 by a sealing material 30 such as a low melting point metal.
[0016]
In the sealed state, the respective projecting portions 18a, 18b, 18c, 18d of the side wall 18 project outward from the front substrate 11 and extend to near the corners of the rear substrate 12. In addition, the protrusions 18a, 18b, 18c, and 18d can function as grips when positioning the side wall in the FED manufacturing process, as described later.
[0017]
As shown in FIGS. 2 and 3, a plurality of plate-shaped spacers 14 are provided as a support member inside the vacuum envelope 10 to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. I have. These spacers 14 are arranged in a direction parallel to the short side of the vacuum envelope 10 and at predetermined intervals along a direction parallel to the long side. The shape of the spacer 14 is not particularly limited, and for example, a columnar spacer or the like can be used.
[0018]
On the inner surface of the front substrate 11, a phosphor screen 16 shown in FIG. 5 is formed. The phosphor screen 16 is constituted by arranging red, green, and blue striped phosphor layers, and a striped black light absorbing layer 20 as a non-light emitting portion located between these phosphor layers. The phosphor layers extend in a direction parallel to the short side of the vacuum envelope, and are arranged at predetermined intervals along a direction parallel to the long side. Note that a metal back layer 17 made of, for example, an aluminum layer is deposited on the phosphor screen 16.
[0019]
As shown in FIG. 3, on the inner surface of the rear substrate 12, a large number of electron-emitting devices 22 each emitting an electron beam are provided as electron emission sources for exciting the phosphor layer of the phosphor screen 16. These electron-emitting devices 22 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. More specifically, a conductive cathode layer 24 is formed on the inner surface of the rear substrate 12, and an insulating film 26 having a number of cavities 25 is formed on the conductive cathode layer. A gate electrode 28 made of molybdenum, niobium, or the like is formed on the insulating film 26. In each cavity 25 on the inner surface of the back substrate 12, a cone-shaped electron-emitting device 22 made of molybdenum or the like is provided.
[0020]
In the FED configured as described above, a video signal is input to the electron-emitting device 22 and the gate electrode 28 formed in a simple matrix system. When the electron emission element 22 is used as a reference, a gate voltage of +100 V is applied when the luminance is the highest. Further, +10 kV is applied to the phosphor screen 16. As a result, an electron beam is emitted from the electron-emitting device 22. The size of the electron beam emitted from the electron-emitting device 22 is modulated by the voltage of the gate electrode 28, and the electron beam excites the phosphor layer of the phosphor screen 16 to emit light, thereby displaying an image. .
[0021]
Next, a method of manufacturing the FED configured as described above will be described in detail. First, a phosphor screen is applied to a plate glass serving as the front substrate 11. In this method, a glass plate having the same size as the front substrate 11 is prepared, and a phosphor stripe pattern is formed on the glass plate by a plotter machine. The plate glass on which the phosphor stripe pattern is formed and the plate glass for the front substrate are placed on a positioning jig, set on an exposure table, and exposed and developed to produce a phosphor screen. Next, a metal back layer 17 made of an aluminum film is formed over the phosphor screen 16.
[0022]
On the other hand, an electron-emitting device is formed on a sheet glass for a rear substrate. In this case, a matrix-shaped conductive cathode layer 24 is formed on a sheet glass, and an insulating film 26 of a silicon dioxide film is formed on the conductive cathode layer by, for example, a thermal oxidation method, a CVD method, or a sputtering method.
[0023]
Thereafter, a metal film for forming a gate electrode such as molybdenum or niobium is formed on the insulating film 26 by, for example, a sputtering method or an electron beam evaporation method. Next, a resist pattern having a shape corresponding to the gate electrode to be formed is formed on the metal film by lithography. Using the resist pattern as a mask, the metal film is etched by a wet etching method or a dry etching method to form a gate electrode 28.
[0024]
Next, the insulating film 26 is etched by wet etching or dry etching using the resist pattern and the gate electrode 28 as a mask to form the cavity 25. Then, after removing the resist pattern, a release layer made of, for example, aluminum or nickel is formed on the gate electrode 28 by performing electron beam evaporation from a direction inclined at a predetermined angle with respect to the surface of the rear substrate 12. Thereafter, for example, molybdenum as a material for forming a cathode is vapor-deposited from a direction perpendicular to the surface of the rear substrate 12 by an electron beam vapor deposition method. Thus, the electron-emitting device 22 is formed inside each cavity 25. Subsequently, the release layer together with the metal film formed thereon is removed by a lift-off method.
[0025]
Further, a plate-shaped support member 14 is sealed on the rear substrate 12 with low-melting glass.
[0026]
Indium is applied as a sealing material 30 to the rear substrate 12 on which the support member 14 is sealed, the front substrate 11 on which the phosphor screen 16 is formed, and the sealing surfaces of the side walls 18 as described above. Here, indium is applied to the inner surfaces of the peripheral portions of the rear substrate 12 and the front substrate 11 and both surfaces of the side wall 18. After that, they are put into the vacuum processing apparatus 100 in a state where they are opposed to each other with a predetermined gap. In the above-described series of steps, for example, a vacuum processing apparatus 100 as shown in FIG. 6 is used.
[0027]
The vacuum processing apparatus 100 includes a load chamber 101, a baking, electron beam cleaning chamber 102, a cooling chamber 103, a getter film deposition chamber 104, an assembling chamber 105, a cooling chamber 106, and an unloading chamber 107 provided in this order. Have. Each of these chambers is configured as a processing chamber capable of performing vacuum processing, and all the chambers are evacuated during the manufacture of the FED. Adjacent processing chambers are connected by a gate valve or the like.
[0028]
The above-described rear substrate 12, side wall 18, and front substrate 11 are loaded into the load chamber 101, and after the inside of the load chamber 101 is evacuated to a vacuum atmosphere, they are sent to the baking and electron beam cleaning chamber 102. In the baking and electron beam cleaning chamber 102, the front substrate, the rear substrate, and the side walls are heated to a temperature of 350 ° C. to release the surface adsorbed gas of each member.
[0029]
Simultaneously with the heating, an electron beam is irradiated from the electron beam generator (not shown) attached to the baking and electron beam cleaning chamber 102 onto the phosphor screen surface of the front substrate 11 and the electron emission element surface of the rear substrate 12. Since this electron beam is deflected and scanned by a deflecting device mounted outside the electron beam generator, it is possible to clean the entire surface of the phosphor screen surface and the electron emission element surface with the electron beam.
[0030]
After the heating and the electron beam cleaning, the front substrate, the rear substrate, and the side wall are sent to the cooling chamber 103 and cooled to a temperature of, for example, about 100 ° C. Subsequently, the front substrate, the rear substrate, and the side wall are sent to a deposition chamber 104 for forming a getter film, where a Ba film is deposited as a getter film outside the phosphor screen. Since the surface of the Ba film can be prevented from being contaminated with oxygen, carbon, or the like, the active state can be maintained.
[0031]
Subsequently, the back substrate 12, the side wall 18, and the front substrate 11 are sent to the assembly chamber 105. In the assembly chamber 105, as shown in FIG. 7, the front substrate 11 and the rear substrate 12 are held on hot plates 131 and 132 in the assembly chamber, respectively, in a state where they are opposed to each other. In a state where the protrusions 18a, 18b, 18c, and 18d of the side wall 18 are gripped by a chucking mechanism (not shown), the side wall 18 is pulled outward along diagonal axes 40 and 42 as shown in FIG. A tension along the longitudinal direction is applied to each of the long side and the short side. Thereby, the side wall 18 is held between the front substrate 11 and the rear substrate 12 in a state where the side wall 18 is maintained flat and in a predetermined shape without causing distortion or twisting.
[0032]
Next, as shown in FIG. 8, after the flat metal plate electrode 134 is inserted between the rear substrate 12 and the side wall 18, the side wall is lowered toward the rear substrate. When the back substrate 12 and the side wall 18 are close to about 1 mm, the side wall is positioned with respect to the back substrate. At this time, the side wall 18 is in a state in which tension is applied outward in the diagonal direction, and is maintained in a flat and stable shape without bending or twisting during positioning. Therefore, the side wall 18 can be easily and accurately positioned with respect to the rear substrate 12. Since the protruding portions 18a, 18b, 18c, and 18d protrude outward from the side wall 18, even in the assembly chamber 105, the side wall 18 can be easily chucked by using these protruding portions and transported. After the alignment that can be performed is completed, the side wall 18 is further lowered. As a result, as shown in FIG. 9, the metal plate electrode 134 comes into contact with these sealing materials while being sandwiched between the sealing material 30 on the side wall 18 and the sealing material 30 on the rear substrate 12. I do.
[0033]
Next, after inserting another metal plate electrode (not shown) having the same shape as the above-described metal plate electrode between the side wall 18 and the front substrate 11, the front substrate is lowered toward the side wall. When the front substrate 11 and the side wall 18 are close to about 1 mm, the front substrate 11 is positioned with respect to the rear substrate 12. After the positioning is completed, the front substrate 11 is further lowered, and the metal plate electrode is sandwiched between the sealing material 30 on the side wall 18 and the sealing material 30 on the front substrate 12 to make contact with the sealing material.
[0034]
Subsequently, a DC current of 140 A is applied to the metal plate electrode 134 and the other metal plate electrodes while a pressure of about 50 kgf is applied to the front substrate 11 and the rear substrate 12 from both sides. Then, this current flows through indium which is the sealing material 30, and the indium generates heat and is melted. As a result, the front substrate 11, the rear substrate 12, and the side wall 18 are joined to each other by indium to form a vacuum envelope.
[0035]
The envelope formed in this manner is cooled to room temperature in the cooling chamber 106 and then taken out of the unloading chamber 107. Through the above steps, the FED is completed.
[0036]
According to the FED configured as described above and the method of manufacturing the same, the back substrate 12, the side walls 18, and the front substrate 11 are sealed in a vacuum atmosphere, and the surface adsorbed gas is used by using both baking and electron beam cleaning. Can be sufficiently released, the getter film is not oxidized, and a sufficient gas adsorption effect can be maintained. Further, by providing the protruding portions 18a, 18b, 18c, 18d that can be gripped on the side wall 18, the side wall 18 can be easily chucked and transported even in a vacuum device. At the same time, by gripping the protrusions 18a, 18b, 18c, and 18d, pulling them outward, and holding the side walls 18 in a state where tension is applied to each side, the side walls 18 are not distorted or twisted in the sealing process. It is possible to maintain a stable shape. Thereby, the side wall 18 can be easily and accurately positioned with respect to the substrate. Therefore, the sealing operation can be completed in a short time, and the manufacturing cost can be reduced and the mass productivity can be improved. Further, since the side walls can be stably bonded, an FED capable of displaying a stable and good image can be obtained.
[0037]
In the above embodiment, the case where the corner portion of the side wall 18 has a square shape has been described, but the present invention can also be applied to the case where the corner portion of the side wall 18 has a curved shape. In this case, as shown in FIG. 10, an intersection 46 extending the inner side of the side wall 18 is regarded as a vertex, and lines connecting the opposing vertices are set as diagonal axes 40 and 42. Then, projections 18a, 18b, 18c, 18d extending outward from the respective corners of the side wall 18 along the diagonal axes 40, 42 are provided. At the time of manufacturing the FED, similarly to the above-described embodiment, a state in which tension along the longitudinal direction is applied to each side of the side wall 18 by gripping the protrusions 18a, 18b, 18c, and 18d and pulling the protrusions outward. Position with.
[0038]
The projecting portions 18a, 18b, 18c, 18d of the side wall 18 may extend from each corner of the side wall along a direction parallel to the long side of the side wall, as shown in FIG. As shown in FIG. 12, a configuration extending from each corner of the side wall along a direction parallel to the short side of the side wall may be adopted. In any case, as in the above-described embodiment, in the manufacturing process of the FED, the protrusions 18a, 18b, 18c, and 18d are pulled outward while being gripped, and the protrusions 18a, 18b, 18c, and 18d are attached to the long and short sides of the side wall 18. Apply tension along the longitudinal direction. Thus, the side wall 18 can be easily and accurately positioned without distortion or twist. In addition, in the embodiment shown in FIGS. 10 to 12, the same operation and effect as in the above-described embodiment can be obtained.
[0039]
The present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist of the invention. The embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiments, the problems described in the column of the problem to be solved by the invention can be solved and the effects described in the column of the effect of the invention can be solved. When the effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.
[0040]
In the above-described embodiment, the side wall may be positioned with respect to the front substrate, or the substrate and the side wall may be put into a vacuum processing apparatus with an electrode for energizing the sealing material attached to the substrate. . The joining and sealing of the constituent members are not limited to the vacuum atmosphere, but can be performed in another atmosphere environment.
[0041]
The shape of the vacuum envelope, the configuration of the support member, the shape of the phosphor screen, the type of the sealing material, and the like are not limited to the above-described embodiments, but can be variously selected as necessary. As the electron-emitting device, a pn-type cold cathode device or a surface conduction electron-emitting device can be used. The inside of the envelope is not limited to a high vacuum, and the present invention can be applied to other image display devices such as a plasma display panel and a liquid crystal display panel.
[0042]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an image display device capable of performing reliable bonding in a short time while maintaining a stable side wall shape, and a method of manufacturing the same.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an FED according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a state where a front substrate of the FED is removed.
FIG. 3 is a sectional view taken along the line AA in FIG. 1;
FIG. 4 is a plan view showing a side wall of the FED.
FIG. 5 is a plan view showing a phosphor screen of the FED.
FIG. 6 is a view schematically showing a vacuum processing apparatus used for manufacturing the FED.
FIG. 7 is a cross-sectional view showing a state in which a front substrate, a side wall, and a rear substrate are arranged to face each other in the vacuum processing apparatus.
FIG. 8 is a cross-sectional view showing a state in which a metal plate electrode is arranged between a front substrate, a side wall, and a rear substrate in the vacuum processing apparatus.
FIG. 9 is an enlarged cross-sectional view showing a state where a metal plate electrode is sandwiched between the back substrate and the side wall.
FIG. 10 is a plan view showing a side wall according to a modification of the present invention.
FIG. 11 is a plan view showing a side wall according to another modification of the present invention.
FIG. 12 is a plan view showing a side wall according to still another modification of the present invention.
[Explanation of symbols]
10: vacuum envelope, 11: front substrate, 12: rear substrate,
14 support member 16 phosphor screen 18 side wall
18a, 18b, 18c, 18d: projecting portion, 22: electron-emitting device,
30: sealing material, 100: vacuum processing device

Claims (8)

An envelope having a front substrate and a rear substrate disposed to face each other, a rectangular frame-shaped side wall provided between peripheral portions of the front substrate and the rear substrate, and a plurality of envelopes formed in the envelope. Pixels, and
The image display device, wherein the side wall has a protruding portion that protrudes outward from each corner in a direction parallel to a side of the side wall and can be gripped. The image display device according to claim 1, wherein each of the protrusions protrudes outward from each corner of the side wall along a direction parallel to a long side of the side wall. The image display device according to claim 1, wherein each of the protrusions protrudes outward from each corner of the side wall along a direction parallel to a short side of the side wall. 4. The image display device according to claim 1, wherein the side wall is bonded to at least one of the back substrate and the front substrate with a low melting point metal. 5. An envelope having a front substrate and a rear substrate disposed to face each other, a rectangular frame-shaped side wall provided between peripheral portions of the front substrate and the rear substrate, and a plurality of envelopes formed in the envelope. And a method for manufacturing an image display device comprising:
Prepare a rectangular frame-like side wall having a protrusion protruding outward from each corner,
Applying tension along the longitudinal direction to each side of the side wall, grasping each protrusion of the side wall and pulling outward,
A method of manufacturing an image display device, comprising positioning and joining the side wall to at least one of the front substrate and the rear substrate while applying the tension. Preparing the side walls having protrusions extending from each corner along the diagonal axis direction, gripping the protrusions, and pulling outward along the diagonal direction of the side walls, each side of the side wall 6. The method according to claim 5, wherein a tension is applied to the portion. The above-mentioned side wall having a protruding portion extending along a direction parallel to the side from each corner portion is prepared, and each of the protruding portions is gripped and pulled outward to apply a tension to the side portion of the side wall. The method for manufacturing an image display device according to claim 5. 8. The method according to claim 5, wherein the positioning and bonding of the side wall are performed in a vacuum atmosphere.

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