JP3719972B2 - Flat panel display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat display device, and more particularly to a flat display device including a plate-like structure having a large number of electron beam transmission holes.
[0002]
[Prior art]
In recent years, flat display devices such as FED (field emission display) and PDP (plasma display panel) have been developed with the aim of space-saving large displays. In particular, as an FED that can be easily increased in size, development of an SED using a surface conduction electron source as an electron source has been underway.
[0003]
The SED has a first substrate and a second substrate that are arranged to face each other with a predetermined gap, and these first and second substrates are surrounded by a vacuum by joining their peripheral parts to each other through a frame-shaped side wall. Make up the vessel. A phosphor layer that emits red, blue, and green light is formed on the inner surface of the first substrate, and an electron emission source that excites the phosphor is formed on the inner surface of the second substrate. Surface conduction electron sources are arranged. Each surface conduction electron source includes an electron emission portion, a pair of electrodes for applying a voltage to the electron emission portion, and the like.
[0004]
A plate-like structure is installed between the first substrate and the second substrate. The plate-like structure has a number of electron beam transmission holes arranged corresponding to each pixel and each surface conduction electron source. Is formed. In addition, a large number of columnar spacers are arranged between the first and second substrates to maintain a gap between these substrates.
[0005]
The electron beam emitted from each electron source passes through the corresponding electron beam transmission hole of the plate-like structure, collides with the desired phosphor by the voltage applied to the first substrate, and causes the phosphor to emit light. . As the plate-like structure, one of a higher voltage, the same voltage, or a lower voltage than the first substrate is selected according to the voltage applied to the first substrate, the screen size, and the pixel pitch.
[0006]
[Problems to be solved by the invention]
When the envelope is manufactured by sealing the first substrate and the second substrate, the first substrate, the second substrate, and the plate-like structure are heated to a high temperature of 300 ° C. or higher. However, when heating, it is difficult to match the thermal expansion coefficients of the first substrate, the second substrate, and the plate-like structure in the entire temperature range from room temperature to 300 ° C. or higher. Therefore, a positional shift due to a difference in thermal expansion occurs between the first substrate, the second substrate, and the plate-like structure, and in some cases, the first substrate and the second substrate may be damaged.
[0007]
As a method for solving this problem, a method is considered in which the fixing between the first substrate, the second substrate, and the plate-like structure is made loose to allow thermal expansion to escape. However, in the case of the FED, the electron beam emitted from the electron source on the second substrate passes through the electron beam transmission hole of the plate-like structure corresponding to the electron source on a one-to-one basis. The first substrate, the second substrate, and the plate-like structure are required to be aligned with high accuracy. Therefore, the mutual positions of the first substrate, the second substrate, and the plate-like structure must be strictly fixed.
[0008]
The present invention has been made in view of the above points, and its purpose is to alleviate the difference in thermal expansion between the first substrate, the second substrate, and the plate-like structure during manufacturing, and the first substrate, the second substrate, or An object of the present invention is to provide a flat display device capable of aligning the first substrate, the second substrate, and the plate structure with high accuracy without causing damage to the plate structure.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a flat display device according to an aspect of the present invention is provided with a first substrate having a phosphor layer formed on an inner surface thereof, opposed to the first substrate, and disposed on the phosphor layer. A second substrate provided with a large number of electron sources for emitting an electron beam toward the substrate, and a plurality of electron beam transmission holes corresponding to the electron sources disposed between the first substrate and the second substrate . A plate-like structure, wherein the plate-like structure is opposed to the phosphor layer and has an effective portion in which the plurality of electron beam passage holes are formed, and a non-layered structure positioned around the effective portion. And a corner portion of the plate structure is fixed to at least one of the first substrate and the second substrate, and the plate structure is formed on the non-hole portion. has formed a plurality of recesses were Netsu膨for the first substrate and the second substrate Thermal expansion absorbing portions to mitigate differences, and is characterized in that it comprises at least one of the thermal expansion absorbing portions to mitigate the thermal expansion difference with respect to the first substrate and the second substrate is formed in the corner portion.
[0010]
In the flat display device having the above-described configuration, the thermal expansion difference between the first substrate, the second substrate, and the plate-like structure during manufacturing is reduced by providing the plate-like structure with a thermal expansion relaxation portion that reduces the thermal expansion difference. In addition, the first substrate, the second substrate, and the plate-like structure can be aligned with high accuracy without destroying the first and second substrates or the plate-like structure.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments in which the present invention is applied to an SED as a flat display device will be described.
[0012]
The SED includes a first substrate 12 and a second substrate 10 made of rectangular glass as insulating substrates, respectively, and the first and second substrates are arranged to face each other with a gap of about 1.0 to 3.0 mm. . The second substrate 10 is formed to have a slightly larger size than the first substrate 12. Further, the peripheral edges of the first substrate 12 and the second substrate are bonded to each other via a rectangular frame-shaped side wall 14 made of glass, thereby forming a flat rectangular vacuum envelope 15. The side wall 14 is sealed to the peripheral portions of the first substrate 12 and the second substrate 10 by, for example, frit glass 20 made of low melting point glass or indium.
[0013]
A phosphor screen 16 is formed on the inner surface of the first substrate 12 using an existing forming method such as screen printing or photolithography. The phosphor screen 16 is configured by arranging phosphor layers R, G, and B that emit red, green, and blue light upon collision of electron beams, and a black colored layer formed between the phosphor layers. . Each phosphor layer R, G, B is formed in a stripe shape or a rectangular dot shape.
[0014]
A metal back 17 made of aluminum or the like is formed on the phosphor screen 16 using a known technique such as vacuum deposition or a lamination method. A transparent conductive film made of, for example, ITO or Nesa (SnO ₂ ) or a color filter film may be provided between the first substrate 12 and the phosphor screen 16.
[0015]
On the inner surface of the second substrate 10, a 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 electron-emitting device 18 includes an electron emitting portion (not shown) and a pair of device electrodes for applying a voltage to the electron emitting portion. On the second substrate 10, a large number of wirings (not shown) for applying a voltage to the electron-emitting devices 18 are provided in a matrix.
[0016]
Between the 1st board | substrate 12 and the 2nd board | substrate 10, the rectangular grid 24 is installed as a plate-shaped structure. A plurality of columnar first and second spacers 30a and 30b are integrally provided on the grid 24 and protrude from both sides of the grid. The first and second spacers 30 a and 30 b are in contact with the inner surfaces of the first substrate and the second substrate, respectively, and support the atmospheric pressure load acting on the vacuum envelope 15.
[0017]
As shown in FIGS. 2 to 4, the grid 24 is formed in a substantially rectangular shape by 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 are formed, and a rectangular frame-shaped non-hole portion 42 positioned around the effective portion.
[0018]
More specifically, the grid 24 has a first surface 24 a facing the inner surface of the first substrate 12 and a second surface 24 b facing the inner surface of the second substrate 10. For example, the four corners of the grid 24 are fixed to at least one of the first substrate 12 and the second substrate 10 and are arranged in parallel with these substrates.
[0019]
The grid 24 is opposed to the phosphor screen 16 and 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-porous portion 42 positioned around the effective portion. And have. The electron beam passage holes 26 are arranged at a predetermined pitch so as to face the electron emitting elements 18. Further, a plurality of spacer openings 28 are formed in the grid 24. These spacer holes 28 are arranged at a predetermined pitch in both the effective portion 40 and the non-hole portion 42.
[0020]
The grid 24 is formed to have a thickness of 0.1 to 0.2 mm using, for example, an iron-nickel metal plate, and an insulating film formed by, for example, applying and baking low-melting glass on the surface thereof. Is formed. This insulating film may be an insulating film made of an oxide film obtained by oxidizing a metal plate. Further, a high resistance film may be formed on these insulating films as necessary.
[0021]
On the first surface 24 a of the grid 24, a first spacer 30 a is integrally provided so as to overlap each spacer opening 28, and the extended end is provided with a black colored layer of the metal back 17 and the phosphor screen 16. Via the inner surface of the first substrate 12. On the second surface 24 b of the grid 24, a second spacer 30 b is integrally provided so as to overlap each spacer opening 28, and its extending end is in contact with the inner surface of the second substrate 10. The spacer holes 28 and the first and second spacers 30 a and 30 b are aligned with each other, and the first and second spacers are integrally connected to each other through the spacer holes 28.
Each of the first and second spacers 30a and 30b is formed in a tapered shape with a diameter decreasing from the grid 24 side toward the extending end.
[0022]
The diameter of each spacer opening 28 is set sufficiently smaller than the diameter of the grid side ends of the first and second spacers 30a and 30b. Then, the first spacer 30a and the second spacer 30b are coaxially aligned and integrally provided with the spacer opening 28, whereby 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 in a sandwiched state.
[0023]
As shown in FIGS. 4 and 5, the grid 24 includes thermal expansion relaxation portions 44 formed at the four corners of the non-hole portion 42 and positioning marks 46 similarly formed at the four corners of the non-hole portion 42. Yes.
[0024]
Each thermal expansion relaxation portion 44 has, for example, 3 mm × 2 mm substantially rectangular first through holes 47 arranged in 2 rows and 3 columns across a bridge 48 having a width of 0.2 mm. Are formed by arranging a pair of elongated second through holes 50 of 1.0 mm × 5.5 mm formed on both sides. The first through hole 47 extends in a direction substantially perpendicular to the diagonal axis of the grid 24, and the second through hole 50 extends in a direction parallel to the diagonal axis.
[0025]
Each thermal expansion relaxation portion 44 is provided between the fixing portion 51 and the effective portion 40 of the grid 24 with respect to the first or second substrate 12 or 10. And each thermal expansion relaxation part 44 exhibits a spring effect, when the 1st board | substrate 12, the 2nd board | substrate 10, and the grid 24 expand | swell, ie, expands-contracts in the surface direction of the grid 24, a board | substrate, a grid, Relieve the thermal expansion difference between.
[0026]
Each positioning mark 46 is formed, for example, by arranging through holes 52 having a diameter of 0.2 mm in 3 rows and 3 columns at a pitch of 0.5 mm. When the SED is assembled, the grid 24 is attached to the first and second substrates with reference to the positioning marks 46 of the grid 24 and positioning marks (not shown) provided on at least one of the first and second substrates 12 and 10. Position.
[0027]
The positioning marks 46 need only be provided in at least two places, and the positions can be arbitrarily selected. The shape of each positioning mark 46 can be selected variously.
[0028]
Next, a method for manufacturing the grid 24, the spacers 30a and 30b configured as described above, and the SED including the grid 24 will be described.
First, as a material for the grid 24, a base material is prepared of an Fe—Ni alloy having a thickness of 0.1 mm. Degreasing the rolling oil and rust preventive oil adhering to this base material with a high-temperature alkaline solution, washing with water, applying a casein resist on both sides of this base material, drying, and a photosensitive film with a thickness of several μm Form. Subsequently, a pair of photomasks are vacuum-contacted on both surfaces of the substrate, and then exposed, and the patterns of these photomasks are baked on the photosensitive film.
[0029]
Next, the photosensitive film on which the pattern is baked is developed using industrial water, the unexposed part is removed, and further, the film is cured with chromic anhydride, washed with water, dried and baked. An etching resist pattern corresponding to the pattern of the pair of photomasks is obtained. Thereafter, the substrate is spray-etched from both sides with a ferric chloride etchant 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, whereby a grid 24 having a large number of electron beam transmission holes is created.
[0030]
Further, when forming the electron beam passage hole 26, simultaneously, the first and second through holes 47 and 50 to be the thermal expansion relaxation portion 44 and the through hole 52 to be the positioning mark 46 are formed by etching. These through holes 47, 50, and 52 can also be formed using laser light, electric discharge machining, or the like after the electron beam passage hole 26 is formed.
[0031]
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.
[0032]
First, the grid 24 is sandwiched between and closely adhered to the first and second molds. 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. Fill the through hole of the mold.
[0033]
Next, after exposing the glass paste with ultraviolet rays, these are baked at about 300 ° C. with the first and second molds in close contact with the grid. Thereby, 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 hole 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 from the glass paste and vitrify the glass filler. Thereby, the first and second spacers 30 a and 30 b are formed on both surfaces of the grid 24.
[0034]
In addition, in the manufacturing method using a metal mold | die, accurate positioning is requested | required between the through-hole of a metal mold | die and the spacer opening 28 of the grid 24. FIG. In the present embodiment, the through holes 52 of the positioning marks 46 formed in the grid 24 are used, and the grid 24 and the mold are aligned with the pins inserted into the through holes.
[0035]
When the SED is manufactured using the grid 24 with the spacer manufactured as described above, the second substrate 10 in which the electron-emitting device 18 is provided and the side wall 14 is bonded, the phosphor screen 16, and A first substrate 10 provided with a metal back 17 is prepared.
[0036]
The grid 24 is positioned on the first or second substrate 10 or 12 using the positioning mark 46 and then 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 the vacuum chamber, the inside of the vacuum chamber is evacuated, and then the first substrate 12 is bonded to the second substrate 10 through the side wall 14. To do. Thereby, SED provided with the grid 24 is manufactured.
[0037]
According to the SED configured as described above, for example, during manufacturing, the first substrate 12, the second substrate 10, and the grid 24 are heated to 300 ° C. or more and thermally expand. These substrates and the grid 24 are formed of materials having substantially the same thermal expansion coefficient, but there is also a difference in heat capacity, and it is difficult to completely match the thermal expansion amounts. However, according to the SED having the above configuration, when a difference in thermal expansion occurs between the first and second substrates 12 and 10 and the grid 24, each thermal expansion relaxation portion 44 of the grid exhibits a spring effect, that is, The film 24 expands and contracts in the plane direction of the grid 24 to absorb or alleviate the difference in thermal expansion between the first and second substrates and the grid. Therefore, damage to the substrate and the grid due to the difference in thermal expansion can be prevented. Thereby, the gradient of temperature rise and temperature drop during manufacture can be made steep, and productivity can be improved.
[0038]
At the same time, the electron beam passage hole 26 of the grid 24 can be held at an accurate position with respect to the phosphor screen 16 on the first substrate 10 and the electron-emitting device 18 on the second substrate 12, thereby improving the image quality. Can be achieved.
[0039]
Actually, as a result of comparing the SED incorporating the grid having the thermal expansion relaxation portion 44 as in the above embodiment and the SED incorporating the grid not having the thermal expansion relaxation portion, the SED according to the present embodiment is compared. Then, the vignetting of the electron beam by the grid 24 decreased, and the brightness of the entire SED increased.
[0040]
In the above-described embodiment, each thermal expansion relaxation portion 44 is formed by a plurality of through holes. However, the present invention is not limited to this, and as shown in FIG. It is formed in a plurality of rows extending in a direction perpendicular to the angular axis. In this case, the thermal expansion of the grid 24, in particular, the thermal expansion along the diagonal axis direction can be effectively mitigated.
[0041]
Moreover, as shown in FIG. 7, each thermal expansion relaxation part 44 may be comprised by the some recessed part 56 by which the grid 24 was pattern-formed by half-etching about 50% of board thickness , for example. According to the thermal expansion relaxation portion 44 shown in FIG. 7A, the plurality of recesses 56 are formed in a plurality of rows extending in a direction perpendicular to the diagonal axis of the grid 24. In this case, the thermal expansion of the grid 24, in particular, the thermal expansion along the diagonal axis direction can be effectively mitigated.
[0042]
According to the thermal expansion relaxation portion 44 shown in FIG. 7C, the plurality of recesses 56 are formed in a plurality of rows extending in an arc shape along the corners of the grid 24. In this case, thermal expansion of the grid 24, particularly thermal expansion along the radial direction with respect to the center of the grid, can be effectively mitigated.
[0043]
Further, the thermal expansion relaxation portion 44 shown in FIG. 8 is formed by a plurality of bent portions 58 obtained by bending a part of the grid 24 into a bellows shape. Each bending part 58 is extended in the direction orthogonal to the diagonal axis | shaft of the grid 24, for example. The height h of the bent portion 58 along the plate thickness direction of the grid 24 is formed to be about 1 mm. In this case, the thermal expansion of the grid 24, in particular, the thermal expansion along the diagonal axis direction of the grid 24 can be effectively reduced.
[0044]
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 position where the grid is fixed with respect to the substrate is not limited to the corner portion of the grid, but can be arbitrarily set such as an intermediate portion of each side of the grid. Similarly, the thermal expansion relaxation portion of the grid is not limited to the corner portion of the grid, and can be arbitrarily set according to the position of the fixed portion.
[0045]
Moreover, the thermal expansion relaxation part of a grid is not limited to a through-hole, a recessed part, and a bending part, If it is a structure which has a spring effect, various selection is possible.
[0046]
Furthermore, the electron source is not limited to the surface conduction electron-emitting device, but can be variously selected such as a field emission type and a carbon nanotube. Further, the present invention is not limited to the above-described SED, but can be applied to other types of FEDs.
[0047]
【The invention's effect】
As described above in detail, according to the present invention, by providing the plate-like structure with the thermal expansion relaxation portion that reduces the difference in thermal expansion, the first substrate, the second substrate, and the plate-like structure at the time of manufacturing are provided. The first substrate, the second substrate, and the plate-like structure can be aligned with high accuracy without reducing the difference in thermal expansion and causing damage to the first substrate, the second substrate, or the plate-like structure. It is possible to provide a flat display device that is improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an SED according to a first embodiment of the present invention.
2 is a perspective view of the SED broken along the line AA in FIG. 1; FIG.
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 plan view showing a thermal expansion relaxation portion of a grid of an SED according to a second embodiment of the present invention.
FIGS. 7A and 7B are a plan view and a cross-sectional view showing a thermal expansion relaxation portion of a grid of an SED according to a third embodiment of the present invention. FIGS.
FIG. 8 is a cross-sectional view showing a thermal expansion relaxation portion of a grid of an SED according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate 12 ... 2nd board | substrate 14 ... Side wall 15 ... Vacuum envelope 16 ... Phosphor screen 18 ... Electron emission element 24 ... Grid 24a ... 1st surface 24b ... 2nd surface 26 ... Electron beam passage hole 28 ... Spacer opening 30a ... 1st spacer 30b ... 2nd spacer 44 ... Thermal expansion relaxation part 46 ... Positioning mark 47, 50, 52 ... Through-hole 54 ... Notch 56 ... Recessed part 58 ... Bending part

Claims (6)

A first substrate having a phosphor layer formed on the inner surface;
A second substrate provided opposite to the first substrate and provided with a number of electron sources for emitting an electron beam toward the phosphor layer;
A plate-like structure disposed between the first substrate and the second substrate and provided with a number of electron beam transmission holes corresponding to the electron source,
The plate-like structure includes an effective portion facing the phosphor layer and having a large number of electron beam passage holes, and a non-hole portion positioned around the effective portion, and is substantially rectangular. And the corners of the plate-like structure are fixed to at least one of the first substrate and the second substrate,
The plate-like structure has a plurality of recesses formed in the non-hole part, and has a thermal expansion relaxation part that relaxes a thermal expansion difference with respect to the first substrate and the second substrate , and the corner part, A flat display device comprising at least one of thermal expansion relaxation portions for relaxing a thermal expansion difference with respect to the first substrate and the second substrate . The flat display device according to claim 1, wherein the thermal expansion relaxation portion has a plurality of recesses formed in corner portions of the plate-like structure. The flat display device according to claim 1, wherein the thermal expansion relaxation part has a plurality of through holes formed in the non-hole part. The flat display device according to claim 1, wherein the thermal expansion relaxation portion has a plurality of bent portions formed in an accordion shape in the non-hole portion. The said plate-shaped structure has the positioning mark formed in the said non-hole part, and aligns with a 1st board | substrate and a 2nd board | substrate, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. Flat display device. A plurality of spacers that maintain a distance between the first substrate and the second substrate;
The spacer is flat display device according to any one of claims 1 to 5, characterized in that it includes a spacer provided integrally on the plate-like structure.

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