JP2004111164A - Flat surface type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat surface type display device in which a damage of a grid at a manufacturing time can be suppressed and which improves a manufacturing yield and reliability. <P>SOLUTION: The flat surface type display device includes the grid 24 provided between a first substrate having a fluorescent substance layer formed on an inner surface and a second substrate having many electron sources for emitting an electron beam toward the substance layer. The grid has a valid section 40 having many electron beam passing holes 26 corresponding to the electron sources and an invalid section 42 disposed on a periphery of the valid section. The invalid section has a thermal deformation relaxing section 44 including a plurality of recesses or through holes 46 to relax a thermal deformation difference between the valid section and the invalid section. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flat-panel display device, and more particularly to a flat-panel display device having a plate-like structure having a large number of electron beam passage holes.
[0002]
[Prior art]
2. Description of the Related Art In recent years, flat display devices such as FEDs (field emission displays) and PDPs (plasma display panels) have been developed with the aim of realizing large-sized displays with a small space. For example, a surface conduction electron-emitting display (hereinafter, referred to as an SED) using a surface conduction electron source is being developed as an FED that can be easily increased in size.
[0003]
The SED has a first substrate and a second substrate which are opposed to each other with a predetermined gap therebetween, and the first and second substrates are joined to each other via a frame-shaped side wall to form a vacuum envelope. Make up the vessel. On the inner surface of the first substrate, a phosphor layer that emits light of three colors, red, blue and green, is formed. On the inner surface of the second substrate, a large number of electron emission sources for exciting the phosphor are provided. A surface conduction electron source is arranged. Each electron source includes an electron emitting portion, a pair of electrodes for applying a voltage to the electron emitting portion, and the like.
[0004]
Further, a rectangular plate-like grid is provided between the first substrate and the second substrate. The grid includes an effective portion having a large number of electron beam passage holes formed therein, and an ineffective portion located around the perforated portion and having no electron beam passage hole. The electron beam passage holes of the effective portion are located corresponding to each pixel and each electron source, and are arranged via an elongated bridge. Further, between the first and second substrates, a number of columnar spacers for maintaining a gap between these substrates are arranged (for example, see Patent Document 1).
[0005]
An electron beam emitted from each electron source passes through a corresponding electron beam passage hole of the grid, is accelerated by a voltage applied to the first substrate, and collides with a desired phosphor. Thereby, the phosphor is excited and emits light, and a desired image is displayed.
[0006]
[Patent Document 1]
JP-A-2001-272927
[0007]
[Problems to be solved by the invention]
However, in the above SED, the bridge portion located between the electron beam passage holes of the grid has a very small width, and the plate thickness of the grid is also formed very thin. Therefore, the grid has a structure in which the mechanical strength is weak in the arrangement direction of the electron beam passage holes. Therefore, phenomena such as breakage and tearing of the bridge portion are likely to occur.
[0008]
Particularly, the manufacturing process of the SED includes a heat treatment process of heating the first substrate, the second substrate, and the grid at a high temperature of 300 ° C. or higher. The volume difference between the effective portion of the grid having a large number of electron beam passage holes and the ineffective portion having no electron beam passage holes is large. Therefore, in the heat treatment step, a difference occurs in the behavior of thermal deformation such as thermal expansion and thermal contraction between the perforated portion and the ineffective portion of the grid. Due to such a difference in thermal deformation behavior, stress acts on the outermost peripheral portion of the perforated portion, and the bridge portion is likely to be damaged, such as being broken, broken, or cracked.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a flat display device which can suppress damage to a grid at the time of manufacturing, and has improved manufacturing yield and reliability.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a flat display device according to one embodiment of the present invention includes a first substrate having a phosphor layer formed on an inner surface thereof, the first substrate facing the first substrate, and the phosphor layer A second substrate provided with a number of electron sources for emitting an electron beam toward the first substrate and a second substrate disposed between the first substrate and the second substrate, and provided with a number of electron beam passage holes corresponding to the electron sources; And a plate-like grid.
[0011]
The grid includes an effective portion having the plurality of electron beam passage holes formed therein, an ineffective portion located around the effective portion and having no electron beam passage hole, and a plurality of concave portions formed in the ineffective portion. And a thermal deformation alleviating portion including a place or a through hole for reducing a thermal deformation difference between the effective portion and the ineffective portion.
[0012]
In the flat-panel display device having the above-described configuration, by providing the grid with a thermal deformation reducing portion that reduces a thermal deformation difference, the heat deformation between the effective portion and the ineffective portion of the grid during the heating process during the manufacturing process is performed. It is possible to reduce the difference in behavior and suppress damage to the grid. As a result, a flat display device with improved manufacturing yield and improved reliability can be obtained.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a SED as a flat display device will be described.
[0014]
As shown in FIGS. 1 and 2, the SED includes a first substrate 10 and a second substrate 12 each made of rectangular glass as an insulating substrate, and the first and second substrates are about 1.0 to 3.0 mm. Are arranged facing each other with a gap of. The second substrate 12 is formed to have a slightly larger dimension than the first substrate 10. Further, the first substrate 10 and the second substrate are joined at their peripheral edges via a rectangular frame-shaped side wall 14 made of glass to form a flat rectangular vacuum envelope 15. The side wall 14 is sealed to the peripheral portions of the first substrate 10 and the second substrate 12 by, for example, frit glass 20 made of low-melting glass or indium.
[0015]
A phosphor screen 16 is formed on the inner surface of the first substrate 10 by using an existing forming method such as a screen printing method or photolithography. The phosphor screen 16 is configured by arranging phosphor layers R, G, B that emit red, green, and blue light by collision of an electron beam, and a black light-shielding layer formed between the phosphor layers. . Each of the phosphor layers R, G, and B is formed in a stripe shape or a rectangular dot shape.
[0016]
On the phosphor screen 16, a metal back 17 made of aluminum or the like is formed by using a known technique such as vacuum deposition or lamination. Note that a transparent conductive film made of, for example, ITO, ATO, or Nesa (SnO ₂ ) or a color filter film may be provided between the first substrate 10 and the phosphor screen 16.
[0017]
On the inner surface of the second substrate 12, a large number of surface conduction electron-emitting devices 18 each emitting an electron beam are formed as electron emission sources for exciting the phosphor layer. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. Each of the electron-emitting devices 18 includes an electron-emitting portion (not shown), a pair of device electrodes for applying a voltage to the electron-emitting portion, and the like. A large number of wirings 11 for applying a voltage to the electron-emitting devices 18 are provided in a matrix on the second substrate 12, and are drawn out of the vacuum envelope 15.
[0018]
A rectangular grid 24 is provided between the first substrate 10 and the second substrate 12 as a plate-like structure. The grid 24 is provided with a plurality of columnar first and second spacers 30a and 30b integrally, and protrudes from both sides of the grid. The first and second spacers 30a and 30b are in contact with the inner surfaces of the first substrate 10 and the second substrate 12, respectively, and support the atmospheric load acting on the vacuum envelope 15.
[0019]
As shown in FIGS. 2 to 4, the grid 24 is formed in a substantially rectangular plate shape from a metal material having a thermal expansion coefficient substantially equal to that of glass. The grid 24 has a rectangular effective portion 40 in which a large number of electron beam passage holes 26 are formed, and a rectangular frame-shaped non-effective portion 42 located around the effective portion.
[0020]
More specifically, the grid 24 has a first surface 24 a facing the inner surface of the first substrate 10 and a second surface 24 b facing the inner surface of the second substrate 12. The grid 24 has, for example, fixing portions 51 at four corners fixed to at least one of the first substrate 10 and the second substrate 12, and is arranged in parallel with these substrates.
[0021]
The grid 24 has a rectangular effective portion 40 facing the phosphor screen 16 and having a number of electron beam passage holes 26 formed therein, and a rectangular frame-shaped non-effective portion 42 located around the effective portion. And The electron beam passage holes 26 are arranged at a predetermined pitch with a narrow bridge portion interposed therebetween, and face the electron-emitting device 18. Each electron beam passage hole 26 is formed in, for example, a rectangular shape having a diameter of about 160 to 200 μm. Further, a plurality of spacer openings 28 are formed in the grid 24. These spacer openings 28 are arranged at a predetermined pitch in both the effective portion 40 and the non-effective portion 42.
[0022]
The grid 24 is formed of, for example, an Fe-45 to 55% Ni alloy to a thickness of about 0.1 to 0.5 mm, and is coated with, for example, a low-melting glass on at least the surface on the second substrate 12 side. Then, an insulating film formed by firing is formed. This insulating film may be composed of an oxide film obtained by oxidizing a metal plate. If necessary, a high resistance film may be formed on these insulating films.
[0023]
On the first surface 24a of the grid 24, a first spacer 30a is integrally erected so as to overlap with each of the spacer openings 28. The first substrate 10 is in contact with the inner surface of the first substrate 10 via the first substrate 10. On the second surface 24b of the grid 24, a second spacer 30b is erected integrally with each of the spacer openings 28, and its extended end is in contact with the inner surface of the second substrate 12. Each of the spacer openings 28 and the first and second spacers 30a and 30b are located in alignment with each other, and the first and second spacers are integrally connected to each other through the spacer openings 28.
Each of the first and second spacers 30a and 30b is formed in a tapered shape having a smaller diameter from the grid 24 side toward the extending end.
[0024]
The diameter of each spacer opening 28 is set sufficiently smaller than the diameter of the first and second spacers 30a, 30b on the grid side. The first spacer 30a and the second spacer 30b are coaxially aligned with the spacer opening 28 and integrally provided, so that the first and second spacers are connected to each other through the spacer opening, and the grid 24 is connected from both sides. It is formed integrally with the grid 24 while being sandwiched.
[0025]
As shown in FIGS. 4 and 5, the effective portion 40 of the grid 24 is formed in a rectangular shape, and has a pair of long sides 40a and a pair of short sides 40b. Further, the non-effective portion 42 of the grid 24 is formed with a thermal deformation reducing portion 44 provided along each of the long side 40a and the short side 40b of the effective portion 24.
[0026]
Each thermal deformation relief section 44 has a plurality of, for example, two, rows of through-hole rows 48 each including a large number of through-holes 46 arranged at intervals. These through-hole rows 48 extend along the outer edge of the effective portion 40, that is, along the long side 40a or 40b of the perforated portion, respectively, and have a gap outward from the outer edge of the effective portion. Are arranged.
[0027]
In the first through-hole row 48 adjacent to the effective portion 40, the diameter of each through-hole 46 is formed to be about 150 μm. The diameter of the through-holes 46 forming the second through-hole row 48 is smaller than the diameter of the through-holes 46 forming the first through-hole row 48, for example, 120 μm. That is, the size of the through-holes 46 constituting each row of the thermal deformation reducing portions 44 is smaller as the through-holes are located outside the outer edge of the effective portion 40. The pitch of the through-holes 46 forming the first through-hole row 48 and the pitch of the through-holes 46 forming the second through-hole row 48 are set to be the same.
[0028]
Note that the through-holes 46 constituting the thermal deformation reducing portion 44 may be formed so that the formation density of the through-holes decreases from the outer edge of the effective portion 40 to the outside. For example, the dimensions of the through holes 46 in the first and second through hole rows 48 may be the same, and the pitch may be set to be larger in the second row than in the first row. Alternatively, the through holes 46 may be formed randomly without being arranged in a row.
[0029]
The distance d between the row of the electron beam passage holes 26 formed on the outermost periphery of the perforated section 40 and the first row of through holes 48 constituting the thermal deformation reduction section 44 is between the electron beam passage holes 26. , Here, the distance D between the electron beam passage holes along a direction parallel to the short side of the effective portion 40 is set to be equal to or smaller than the distance D.
[0030]
In the present embodiment, when the interval D between the electron beam passage holes 26 is 600 to 650 μm, the interval d is set to 600 to 650 μm.
The thermal deformation reducing portions 44 formed by the through holes 46 are provided along the substantially entire lengths of the long sides and the short sides outside the long sides 40a and the short sides 40b of the effective portion 40. I have.
[0031]
Next, a method of manufacturing the grid 24 and the spacers 30a and 30b configured as described above and an SED including the same will be described.
First, a base material made of an alloy of Fe-50% Ni having a plate thickness of 0.12 mm is prepared as a material of the grid 24. Rolling oil, rust-preventive oil and the like adhering to the substrate are degreased with a high-temperature alkaline solution, washed with water, and then coated with casein-based resist on both sides of the substrate and dried. Subsequently, a photosensitive film having a thickness of several μm is formed on the surface of the substrate. Next, a pair of photomasks are vacuum-contacted on both sides of the substrate, and then exposed, and the patterns of these photomasks are printed on a photosensitive film.
[0032]
Thereafter, the photosensitive film on which the pattern was baked is developed using working water to remove unexposed portions, and further subjected to hardening treatment with chromic anhydride, washing with water, drying and baking. An etching resist pattern corresponding to the pattern of the photomask is obtained. Subsequently, the base material is spray-etched from both sides with a ferric chloride etching solution in accordance with the etching resist pattern to form a large number of electron beam passage holes 26. Then, the substrate is washed with water, and finally, the resist pattern is peeled off with an alkaline solution to form a grid 24 having a large number of electron beam passage holes.
[0033]
Further, when forming the electron beam passage holes 26, at the same time, the through holes 46 serving as the thermal deformation relaxation portions 44 are formed by etching. At this time, the hole diameter of the electron beam passage hole 26 is about 180 μm, a through hole 46 of about 150 μm is formed outside the effective portion 40 in the same arrangement as the electron beam passage hole, and a through hole 46 of about 120 μm is further formed outside the hole. Form. The diameter of each through hole is a diameter measured on the surface of the base material. Note that the through-hole 46 can also be formed by using a laser beam, electric discharge machining, or the like after forming the electron beam passage hole 26.
[0034]
Next, the grid 24 is blackened at about 580 ° C. in order to prevent rust and improve the adhesion to the glass paste for forming the spacer. Further, the grid 24 subjected to the blackening treatment is subjected to a glass coating treatment to form an insulating layer. Also at this time, a heat treatment of about 550 ° C. is performed on the grid 24.
[0035]
Subsequently, columnar spacers are formed on both sides of the grid 24 using a mold. Two molds are prepared: a first mold for spacers formed on the first surface 24a of the grid 24 and a second mold for spacers formed on the second surface 24b. Each mold has a plate shape having through holes corresponding to the shape of the spacer to be formed, and these through holes are provided at positions corresponding to the spacer openings 28 of the grid 24.
[0036]
First, the grid 24 is sandwiched between the first and second molds and brought into close contact therewith. In this state, a glass paste containing an ultraviolet curable resin and a glass filler is supplied from the through-hole side of the first mold, and the through-hole of the first mold, the spacer opening 28 of the grid 24, and the second mold are provided. Fill the mold through holes.
[0037]
Next, after exposing the glass paste with ultraviolet rays, these are fired at about 300 ° C. in a state where the first and second molds are in close contact with the grid. As a result, the resin applied to the inner surfaces of the through holes of the first and second molds is decomposed and removed, and a gap is formed between the through holes and the spacer. Thereafter, the first and second molds are removed from the grid 24 and heated to 500 ° C. or higher to burn off the resin component from the glass paste and to vitrify the glass filler. Thus, the first and second spacers 30a and 30b are formed on both surfaces of the grid 24.
[0038]
When the SED is manufactured using the grid 24 with spacers manufactured as described above, the second substrate 12 on which the electron-emitting devices 18 are provided and the side walls 14 are bonded in advance, the phosphor screen 16 and The first substrate 10 provided with the metal back 17 is prepared.
[0039]
Then, after positioning the grid 24 on the first or second substrate 10 or 12, the grid 24 is fixed to the first or second substrate. In this state, the first and second substrates 10 and 12 and the grid 24 are arranged in a vacuum chamber, and after evacuating the vacuum chamber, the first substrate 10 is bonded to the second substrate 12 via the side wall 14. I do. Thus, an SED having the grid 24 is manufactured.
[0040]
According to the SED configured as described above, in the manufacturing process, the grid 24 is subjected to a heat treatment such as a blackening process or an insulating layer formation, and is heated to 500 ° C. or more. Then, during the heat treatment, the grid 24 thermally expands. At this time, since the grid 24 includes the thermal deformation reducing portion 44 provided in the non-effective portion 42, the volume difference between the effective portion 40 and the non-effective portion 42 of the grid near the interface is reduced. . Therefore, a difference in behavior between the effective portion 40 and the non-effective portion 42 due to thermal expansion can be reduced. Thereby, the stress acting on the bridge portion or the like of the perforated portion 40 having low mechanical strength can be reduced, and the damage of the grid such as the bridge portion torn, cracked or broken can be suppressed. Therefore, it is possible to obtain an SED with improved manufacturing yield and improved reliability. Further, the gradient of the temperature rise and temperature decrease in the heat treatment step during manufacturing can be made steep, and the productivity can be improved.
[0041]
In the above-described embodiment, each thermal deformation reducing portion 44 is formed by a plurality of through holes 46. However, the present invention is not limited to this. For example, as shown in FIG. A plurality of recesses 50 patterned by etching may be used. In this case, the plurality of recesses 50 can be formed in the same pattern as the through-hole 46 described above. Then, even when each of the thermal deformation reducing portions 44 is constituted by the plurality of recesses 50, the same thermal deformation reducing effect as described above can be obtained.
[0042]
In addition, the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, the thermal deformation reducing portion of the grid is provided along the long side and the short side of the perforated portion. However, if it is provided at least outside the long side of the perforated portion, the thermal deformation reducing effect of the grid is provided. Can be obtained. At the same time, the thermal deformation reducing portion is not limited to being provided over the entire length of the long side or the short side, and may be provided outside at least a part of the long side.
[0043]
The through-holes or recesses constituting the thermal deformation reducing portion of the grid are not limited to a rectangular shape, but may have any shape. The number of through holes or recesses, the density, the number of rows, and the like can be increased or decreased as necessary.
[0044]
Further, the electron source is not limited to the surface conduction type electron-emitting device, and various types such as a field emission type and a carbon nanotube can be selected. Further, the present invention is not limited to the above-described SED, but is applicable to other types of flat display devices.
[0045]
【The invention's effect】
As described in detail above, according to the present invention, the difference in thermal deformation between the effective portion and the ineffective portion of the grid is reduced in the ineffective portion of the grid, and the stress acting on the effective portion is reduced. By providing the thermal deformation reducing portion, damage to the grid during manufacturing can be suppressed, and a flat display device with improved manufacturing yield and reliability can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an SED according to an embodiment of the present invention.
FIG. 2 is a perspective view of the SED taken along line AA in FIG. 1;
FIG. 3 is an enlarged sectional view showing the SED.
FIG. 4 is a plan view of a grid in the SED.
FIG. 5 is an enlarged plan view showing a part of the grid.
FIG. 6 is a sectional view showing a thermal deformation reducing portion of a grid of an SED according to a second embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 10 first substrate 12 second substrate 14 side wall 15 vacuum envelope 16 phosphor screen 18 electron emitting element 24 grid 26 electron beam passage hole 28 spacer opening 30a first spacer 30b 2nd spacer 44 ... thermal deformation relief section 46 ... through hole 50 ... recess

Claims (9)

A first substrate having a phosphor layer formed on an inner surface thereof;
A second substrate disposed opposite to the first substrate and provided with a number of electron sources for emitting an electron beam toward the phosphor layer;
A plate-shaped grid disposed between the first substrate and the second substrate, provided with a large number of electron beam passage holes corresponding to the electron sources,
The grid includes an effective portion having the plurality of electron beam passage holes formed therein, an ineffective portion located around the effective portion and having no electron beam passage hole, and a plurality of concave portions formed in the ineffective portion. A flat display device, comprising: a thermal deformation reducing portion including a place or a through hole and configured to reduce a thermal deformation difference between the effective portion and the ineffective portion. The effective portion is formed in a rectangular shape having a long side and a short side, and the thermal deformation reducing portion of the ineffective portion is provided at least outside each long side of the effective portion. The flat panel display according to claim 1. The effective portion is formed in a rectangular shape having a long side and a short side, and the thermal deformation reducing portion of the ineffective portion is provided over substantially the entire length of each long side outside each long side of the effective portion. The flat panel display according to claim 1, wherein: The effective portion is formed in a rectangular shape having a long side and a short side, and the thermal deformation reducing portion of the ineffective portion is outside each long side and each short side of the effective portion, and each long side and each The flat display device according to claim 1, wherein the flat display device is provided along a short side. The thermal deformation reduction section has a plurality of rows each including a plurality of recesses or through holes arranged at intervals, and these rows extend along the outer edge of the effective section, respectively. 5. The flat display device according to claim 1, wherein the flat display devices are arranged with a gap from the outer edge to the outside. The recesses or through-holes constituting each row of the thermal deformation reducing portions are formed to be smaller in size as the recesses or through-holes of rows located outside the outer edge of the effective portion. 6. The flat panel display according to 5. The electron beam passing holes of the effective portion are formed in a plurality of rows at a predetermined interval, and the interval between the outermost row of the electron beam passing holes and the row of the thermal deformation reducing portions is formed to be equal to or less than the predetermined interval. The flat display device according to claim 5, wherein The flat display device according to any one of claims 1 to 7, wherein the grid is formed of a metal plate having at least a surface on a second substrate side covered with an insulating layer. A plurality of spacers that maintain a distance between the first substrate and the second substrate;
9. The flat display device according to claim 1, wherein the spacer includes a spacer integrally provided on the grid.

Images