JP3782347B2 - Flat display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat display device having a flat shape, and more particularly to a flat display device in which a large number of electron-emitting devices are provided in a vacuum display device and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, various flat display devices have been developed as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter referred to as CRTs). Such flat display devices include a liquid crystal display (hereinafter referred to as LCD) that controls the intensity of light by utilizing the orientation of liquid crystal, and a plasma display panel (hereinafter referred to as PDP) that emits phosphors by ultraviolet rays of plasma discharge. Field emission display (hereinafter referred to as FED) that emits a phosphor with an electron beam of a field emission electron emitter, and a surface conduction electron emission display that emits a phosphor with an electron beam of a surface conduction electron emitter. (Hereinafter referred to as SED).
[0003]
Among these, for example, a vacuum envelope used for an FED or SED is usually provided with a front substrate and a rear substrate which are arranged to face each other, and the peripheral portions of these substrates are sealed together. Further, in order to secure the distance between the front substrate and the rear substrate on the order of mm, the gap cannot be filled with the sealing material alone, and a rectangular frame-shaped side wall is disposed in the sealing region between the peripheral portions of the two substrates. And two sealing layers formed between the front substrate and the back substrate.
[0004]
As a manufacturing method of such an envelope, for example, according to the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 2000-229825, the back substrate and the side wall are bonded in advance in an air atmosphere with frit glass, The side wall joined to the back substrate and the front substrate are sealed with a sealing material in a vacuum chamber to form a vacuum envelope. As the sealing material, a low-melting-point metal material such as indium that melts at a low temperature and emits less gas in vacuum is used.
[0005]
[Problems to be solved by the invention]
In the vacuum envelope manufacturing method described above, since frit glass is used for joining the back substrate and the side wall, the frit glass needs to be softened at a high temperature of about 400 ° C., and the frit glass must be pre-baked. There are problems with mass productivity. Moreover, since frit glass contains lead, an alternative is necessary also in terms of environment.
[0006]
In order to solve such a problem, the present inventors tried to solve the problem by using a low-melting-point metal material such as indium instead of frit glass for joining the back substrate and the side wall. Moreover, examination which seals two sealing layers at once in a vacuum chamber was performed.
[0007]
However, when indium melts, the viscosity is very low, and the thickness of the two sealing layers varies greatly depending on the location due to the weight and warpage of the side walls, especially when the lower sealing layer is crushed and thinned. It was happening. For this reason, there is a problem that the airtightness of the sealed portion is deteriorated due to partial lack of the sealing material, or the protrusion failure due to excessive sealing material is increased.
[0008]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a flat display device having a sealed portion with high airtightness and improved reliability and a method for manufacturing the same.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a flat display device according to the present invention includes a front substrate and a rear substrate that are arranged opposite to each other , and a conductive material that is disposed between peripheral portions of the front substrate and the rear substrate. A substantially frame-shaped side wall, a sealing layer sealed between the back substrate and the side wall, a sealing layer sealed between the front substrate and the side wall, and the front substrate and the back substrate And a spacer member provided between at least one of the front substrate and the back substrate and the side wall and maintaining the sealing layer at a predetermined thickness. It is characterized by that.
[0010]
In addition, the flat display device manufacturing method according to the present invention includes a front substrate and a back substrate that are arranged to face each other, a substantially frame-like side wall that is disposed between peripheral edges of the front substrate and the back substrate, and the back substrate. A sealing layer sealed between the front substrate and the side wall, a sealing layer sealed between the front substrate and the side wall, and a plurality of spacers provided between the front substrate and the rear substrate. In the manufacturing method of the flat display device,
The side wall is formed of a conductive material, and the sealing material is heated and melted and sealed in a state where the sealing material and the spacer member are disposed between one of the rear substrate and the front substrate and the side wall. After the one substrate and the side wall are sealed by forming an adhesion layer, and the one substrate and the side wall are sealed, the one substrate is positioned below the other substrate, A sealing material disposed between the other substrate and the side wall and a sealing material of the sealing layer sealing the one substrate and the side wall are heated and melted to heat and melt the side wall, the back substrate, and the front substrate. A sealing layer is formed between each of the two sealing layers, and at that time, the sealing material of at least one sealing layer of the two sealing layers is melted and sealed by applying current to the side wall and heating. It is characterized by doing.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention applied to an FED as a flat display device will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, the FED includes a transparent rectangular insulating substrate, for example, a back substrate 11 and a front substrate 12 made of a glass plate, and these substrates face each other with a predetermined gap. Has been placed. The rear substrate 11 and the front substrate 12 are joined to each other at peripheral edges via a rectangular frame-shaped side wall 13 made of glass to constitute a flat rectangular vacuum envelope 18.
[0012]
A phosphor screen 16 is formed on the inner surface of the front substrate 12. The phosphor screen 16 is configured by arranging red, blue, and green phosphor layers and a black colored layer. These phosphor layers are formed in stripes or dots. A metal back 17 made of aluminum or the like and functioning as an anode electrode is formed on the phosphor screen 16.
A large number of electron-emitting devices 20 are provided in a matrix on the inner surface of the back substrate 11 and face the phosphor screen 16.
[0013]
The substantially rectangular frame-shaped side wall 13 that functions as a joining member is sealed to the peripheral edge portion of the back substrate 11 via the sealing layer 15a, and to the sealing portion of the front substrate 12 via the sealing layer 15b. Sealed. Accordingly, the peripheral portions of the back substrate 11 and the front substrate 12 are airtightly bonded to each other via the side wall 3. As a sealing material for forming the sealing layers 15a and 15b, a low melting point metal material such as indium is used.
[0014]
Between the back substrate 11 and the front substrate 12, a large number of spacers 14 each formed in a plate shape or a column shape are arranged in order to maintain the distance between the substrates. Both ends of the spacer 14 are in contact with the back substrate 11 and the front substrate 12, respectively, thereby supporting the atmospheric pressure load acting on these substrates and maintaining the distance between the substrates at a predetermined value.
[0015]
As shown in FIGS. 2 and 3, a wall-like spacer member 22 extending along the outer peripheral edge and the inner peripheral edge is integrally projected on the lower surface side of the side wall 13, that is, the surface on the rear substrate 11 side. ing. The side wall 13 is in contact with the back substrate 11 via the spacer member 22. Further, the sealing layer 15 a that seals between the side wall 13 and the back substrate 11 is located between the spacer members 22.
[0016]
According to the FED having the above-described configuration, the electron-emitting device applies electrons to the phosphor screen 16 by applying a voltage to the electron-emitting device 20 through a drive wiring (not shown) formed on the back substrate 11. discharge. Thereby, the phosphor layer of the phosphor screen 16 is excited to emit light, and an image is displayed.
[0017]
Next, a method for manufacturing the FED configured as described above will be described.
For example, when a 36-inch TV FED is manufactured, a glass plate having a thickness of 2.8 mm is prepared as the rear substrate 11 and the front substrate 12, and a frame-shaped glass having a width of 10 mm and a height of 1 mm is used as the side wall 13. Prepare the materials. On one side of the side wall 13, two wall-shaped spacer members 22 having a width of 1 mm and a height of 0.3 mm are formed integrally with the side wall along the inner and outer peripheral edges of the side wall 13. . It is desirable that the height of the spacer member 22 is 0.1 mm or more.
[0018]
Then, the electron-emitting device 20 and various wirings are formed on the back substrate 11. Further, the spacer 14 is fixed on the back substrate 11 in advance using a low melting point metal sealing material such as frit glass or indium. A phosphor screen 16 and a metal back 17 made of an aluminum film are formed on the front substrate 12. Further, both sides of the side wall 13 are filled with indium 25a and 25b having a width of 3 mm and a thickness of 0.4 mm over the entire circumference.
[0019]
Here, indium is an excellent sealing material that has an extremely low melting point of 156 ° C., and has an extremely small outgassing even when heated in vacuum, and hardly deteriorates the characteristics of the FED.
[0020]
Subsequently, the back substrate 11, the front substrate 12, and the side wall 13 prepared as described above are sealed at once in a vacuum chamber to form a vacuum envelope 18. That is, as shown in FIG. 4, in a state where the rear substrate 11 and the front substrate 12 are arranged opposite to each other with the side wall 13 interposed therebetween, these are fed into the vacuum chamber. At this time, the rear substrate 11 is on the lower side, and the side wall 13 is disposed in a state in which the spacer member 22 faces downward, that is, in a state in which the spacer member 22 protrudes toward the rear substrate 11 side.
[0021]
And these are heated, the surface adsorption gas of each member is discharge | released, Furthermore, after cooling these members with an electron beam, it cools once. Subsequently, the back substrate 11, the front substrate 12, and the side wall 13 are heated to about 180 ° C. in the vacuum chamber, and the indiums 25a and 25b are sufficiently melted. In this state, the back substrate 11 and the front substrate 12 are pressurized in a direction approaching each other, and the back substrate 11 and the side wall 13 and the front substrate 12 and the side wall are simultaneously sealed by the sealing layers 15a and 15b made of indium 25a and 25b. To wear.
[0022]
At this time, the melted indium 25a and 25b are in a very low viscosity state. However, since the side wall 13 includes the spacer member 22 that comes into contact with the back substrate 11, the sealing layer 15a positioned between the side wall and the back substrate is not excessively crushed by the weight of the side wall, and is predetermined. A thick sealing layer can be formed. As for the sealing layer 15b located between the side wall 13 and the front substrate 12, a spacer 14 is provided between the back substrate 11 and the front substrate 12, and a spacer member 22 is provided on the side wall. Therefore, it is kept at a predetermined thickness without being excessively crushed by the front substrate.
Thereafter, the rear substrate 11, the front substrate 12, and the side wall 13 are cooled, and the sealing layer is solidified, whereby the FED vacuum envelope 18 is formed.
[0023]
According to the FED configured as described above and the manufacturing method thereof, since the two sealing layers 15a and 15b can be sealed by heating at a low temperature, the mass productivity of the FED is greatly improved. At the same time, by providing the spacer member 22 integral with the side wall between the side wall 13 and the back substrate 11, the sealing layers 15a and 15b can be maintained at a predetermined thickness over the entire circumference. Accordingly, it is possible to obtain an FED with high airtightness of the sealing portion and high reliability by reducing deterioration of the airtightness of the sealing portion due to partial lack of the sealing material, or by reducing the protrusion failure due to excessive sealing material. .
[0024]
In the above-described embodiment, the side wall 13 may be formed of a conductive material, for example, a high melting point material containing at least one of Fe, Cr, Ni, and Al. In this case, only the sealing region can be heated and sealed by energizing the side wall, which further improves mass productivity. In addition, although indium is used as the sealing material, other sealing materials that are similarly low in viscosity and cannot maintain the thickness of the sealing layer against the weight and warpage of the side walls, for example, indium alloys, Metal solder or the like may be used.
[0025]
Furthermore, in the above-described embodiment, the configuration in which two sealing portions are sealed at a time in the vacuum chamber has been shown. However, one sealing portion, that is, one side of the substrate is previously sealed with a sealing material such as indium. It is good also as a structure which joins between side walls, or the structure which performs all sealing in air | atmosphere atmosphere.
[0026]
Next, an FED and a method for manufacturing the same according to a second embodiment of the present invention will be described.
As shown in FIG. 5, according to the present embodiment, the back substrate 11 and the side wall 13 are previously bonded in the air atmosphere by the sealing layer 15a made of indium, and then the front substrate is made of indium 15b in the vacuum chamber. 12 and the side wall 13 are sealed. By sealing the two sealing parts in two steps, the positioning in the vacuum chamber is simplified only to the positioning between the back substrate 11 and the front substrate 12, improving the mass productivity and reducing the environmental load. It is intended to improve.
[0027]
In the sealing step in the vacuum chamber, indium 25a of the sealing layer 15a joining the side wall 13 and the back substrate 11 is melted together with melting of the indium 25b, but the sealing is performed by the spacer member 22 provided on the side wall 13. The layer 15a can be prevented from being crushed and maintained at a predetermined thickness.
[0028]
In the second embodiment, the spacer member 22 on the outer peripheral side of the side wall 13 is provided intermittently with respect to the entire periphery of the side wall, and excess indium 25a is removed from the gap 23 of the spacer member 22 on the outer peripheral side during sealing. It was made the composition which can escape. Further, the width of the side wall 13 was narrowed from 10 mm to 8 mm, and the filling width of the indium 25a was increased from 3 mm to 5 mm.
[0029]
As a result, the width of the side wall 13 can be reduced to narrow the frame of the FED, and at the same time, as in the first embodiment described above, the hermeticity of the sealing portion is increased and the reliability is improved. be able to.
Other configurations are the same as those of the first embodiment described above, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.
[0030]
In the above-described embodiment, the spacer member 22 is formed integrally with the side wall 13. However, these spacer members only need to be provided between the back substrate 11 and the side wall, and are formed separately from the side wall. Also good.
[0031]
As shown in FIG. 6, according to the third embodiment, metal beads having a diameter of 0.3 mm are previously provided as spacer members 22 in indium forming the sealing layer 15a between the back substrate 11 and the side wall 13. I am buried. Other configurations are the same as those of the first embodiment described above, and the same portions are denoted by the same reference numerals and detailed description thereof is omitted.
[0032]
Also in the third embodiment, the sealing layers 15a and 15b can be maintained at a predetermined thickness, and a highly reliable FED with improved airtightness can be obtained, and the processing of the side wall 13 is facilitated and mass productivity is improved. Further improvement is possible.
[0033]
As shown in FIGS. 7 and 8, according to the fourth embodiment, a small rectangular block is used as the spacer member 22, and a plurality of spacer members are arranged between the side wall 13 and the back substrate 11. Are arranged intermittently with a predetermined gap around the entire circumference. In this case, the spacer members 22 are arranged to face the inner peripheral side and the outer peripheral side of the side wall 13 one by one.
[0034]
And the arrangement number of the spacer member 22 is kept to the minimum according to the rigidity of the side wall 13 to be used. Thereby, the mass productivity concerning a spacer member can be improved.
[0035]
Further, as shown in FIG. 9, the spacer members 22 may be arranged alternately on the inner and outer peripheries of the side walls 13, thereby minimizing the width reduction amount of the sealing layer 15 a in the portion where the spacer members 22 are arranged. Limit.
Other configurations are the same as those of the above-described first embodiment, and the same effects as those of the first embodiment can be obtained.
[0036]
As shown in FIG. 10, according to the fifth embodiment of the present invention, in addition to the spacer member 22 provided between the side wall 13 and the back substrate 11, the space between the side wall 13 and the front substrate 12 is provided. Also, another spacer member 24 is provided.
[0037]
That is, on the lower surface of the side wall 13 facing the back substrate 11, a wall-like spacer member 22 extending along the outer peripheral edge and the inner peripheral edge is integrally projected from the lower surface as in the first embodiment. . The side wall 13 is in contact with the back substrate 11 via the spacer member 22. The sealing layer 15 a that seals between the side wall 13 and the back substrate 11 is located between the spacer members 22.
[0038]
Further, a wall-like spacer member 24 extending along the outer peripheral edge and the inner peripheral edge is integrally projected on the upper surface of the side wall 13 facing the front substrate 12. The side wall 13 is in contact with the front substrate 12 via the spacer member 24. The sealing layer 15 b that seals between the side wall 13 and the front substrate 12 is located between the spacer members 24.
Other configurations are the same as those of the first embodiment described above, and the same portions are denoted by the same reference numerals and detailed description thereof is omitted.
[0039]
Also in the fifth embodiment configured as described above, the same operational effects as those of the first embodiment described above can be obtained. In addition, according to the fifth embodiment, by providing the spacer member 24 also between the side wall 13 and the front substrate 12, the side wall and the substrate are lifted by the warp of the side wall 13, and the sealing layer 15a, The variation in the thickness of 15b can be reduced. Therefore, an FED having high airtightness and further improved reliability can be obtained.
[0040]
In the fifth embodiment, the spacer member 24 may have the spacer member structure shown in the second to fourth embodiments described above. In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the present invention is not limited to a vacuum envelope of FED or SED, but can be applied to other flat display devices such as PDP.
[0041]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a flat panel display device that is excellent in mass productivity and has high sealing performance and improved reliability, and a method for manufacturing the same.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a flat display device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the flat display device taken along line AA in FIG.
FIG. 3 is a perspective view showing a part of a side wall of the flat display device.
FIG. 4 is a cross-sectional view showing a manufacturing process of the flat display device.
FIG. 5 is a sectional view showing a manufacturing process of a flat display device according to a second embodiment of the invention.
FIG. 6 is a sectional view showing a flat display device according to a third embodiment of the invention.
FIG. 7 is a sectional view showing a flat display device according to a fourth embodiment of the invention.
FIG. 8 is a plan view showing a rear substrate, a side wall, and a spacer member of the flat display device according to the fourth embodiment.
FIG. 9 is a plan view showing a modification of the flat display device according to the fourth embodiment.
FIG. 10 is a sectional view showing a flat display device according to a fifth embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Back substrate 12 ... Front substrate 13 ... Side wall 14 ... Spacer 15a, 15b ... Sealing layer 16 ... Phosphor screen 17 ... Metal back layer 18 ... Vacuum envelope 20 ... Electron emission element 22, 24 ... Spacer member 25a, 25b ... Indium

Claims (13)

A front substrate and a rear substrate disposed opposite to each other;
A substantially frame-shaped side wall formed of a conductive material and disposed between the peripheral portions of the front substrate and the rear substrate;
A sealing layer sealed between the back substrate and the side wall and a sealing layer sealed between the front substrate and the side wall;
A plurality of spacers provided between the front substrate and the back substrate;
A spacer member provided between at least one of the front substrate and the rear substrate and the side wall, and maintaining the sealing layer at a predetermined thickness;
A flat display device.   2. The flat display device according to claim 1, wherein the two sealing layers are each formed of a sealing material that melts or softens at substantially the same melting point or softening point.   3. The flat display device according to claim 1, wherein the spacer member is integrally formed with the side wall.   3. The flat display device according to claim 1, wherein the spacer member is disposed adjacent to the sealing layer.   The flat display device according to claim 1, wherein the spacer member is disposed so as to be buried in the sealing layer.   The flat panel display according to claim 1, wherein the spacer member is intermittently disposed with respect to the entire circumference of the side wall.   7. The flat display device according to claim 1, wherein the spacer member has a height of 0.1 mm or more.   The flat display device according to claim 1, wherein the sealing layer adjacent to the spacer member is formed of metal solder.   9. The flat display device according to claim 1, wherein the sealing layer contains indium. Between the front substrate and the side wall, and between the rear substrate and the sidewall, claims 1, characterized in that spacer members that maintain the sealing layer to a predetermined thickness are provided, respectively 9 The flat display device according to any one of the above. The front substrate and the rear substrate arranged opposite to each other, the substantially frame-like side wall disposed between the peripheral portions of the front substrate and the rear substrate, the sealing layer sealed between the rear substrate and the side wall, and the front surface In a manufacturing method of a flat display device comprising: a sealing layer that seals between a substrate and a side wall; and a plurality of spacers provided between the front substrate and the back substrate.
The sidewall is formed of a conductive material,
In a state where a sealing material and a spacer member are disposed between one of the back substrate and the front substrate and the side wall, the sealing material is heated and melted to form a sealing layer. And sealed
After sealing the one substrate and the side wall, the sealing material disposed between the other substrate and the side wall in a state where the one substrate is positioned below the other substrate and the one side the sealing material of the sealing layer which is sealed a substrate and the side wall is heated and melted to form a respective sealing layer between the side walls and the rear substrate and the front substrate, in which a current to the side wall A method of manufacturing a flat display device, comprising: energizing and heating to melt and seal a sealing material of at least one of the two sealing layers . The front substrate and the rear substrate arranged opposite to each other, the substantially frame-like side wall disposed between the peripheral portions of the front substrate and the rear substrate, the sealing layer sealed between the rear substrate and the side wall, and the front surface In a manufacturing method of a flat display device comprising: a sealing layer that seals between a substrate and a side wall; and a plurality of spacers provided between the front substrate and the back substrate.
The sidewall is formed of a conductive material,
A sealing material and a spacer member are disposed between one of the back substrate and the front substrate and the side wall,
Placing a sealing material between the other of the back substrate and the front substrate and the side wall;
In the state where the one substrate is positioned below the other substrate, the sealing material is heated and melted to form a sealing layer between the side wall and the back substrate and the front substrate, respectively , A method of manufacturing a flat display device, wherein the side wall is heated by applying an electric current to melt and seal the sealing material of at least one of the two sealing layers . 13. The method for manufacturing a flat display device according to claim 11, wherein a low melting point metal material containing at least indium or an indium alloy is used as the sealing material.

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