JP2005235620A - Plane display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plane display device and its manufacturing method with improved reliability and display quality by preventing deterioration or destruction of a circuit relevant to discharge. <P>SOLUTION: A spacer structure 22 is provided between a first substrate 10 on which a fluorescent surface is formed and a second substrate 12 provided with a plurality of electron emission sources 18. The spacer structure faces the first and the second substrates and has a grid 24 with a plurality of electron beam through holes 26 facing the electron emission sources respectively and a plurality of spacers erected on the surface of the grid. The grid have a plurality of metal wires 44 and a plurality of glass wires 42 intersecting the metal wires and extended and is formed in a mesh. At least one of end parts of the metal wires is electrically connected each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flat panel display device including substrates disposed opposite to each other and spacers disposed between the substrates, and a method for manufacturing the same.

  2. Description of the Related Art In recent years, various flat-type image display devices have attracted attention as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter referred to as CRTs). For example, a surface conduction electron-emitting device (hereinafter referred to as SED) is being developed as a kind of field emission device (hereinafter referred to as FED) that functions as a flat display device.

  The SED includes a first substrate and a second substrate that are arranged to face each other at a predetermined interval, and these substrates form a vacuum envelope by joining peripheral portions to each other through rectangular side walls. ing. A phosphor layer of three colors is formed on the inner surface of the first substrate, and on the inner surface of the second substrate, a large number of electron-emitting devices corresponding to each pixel are arranged as an electron emission source for exciting the phosphor. . In order to support an atmospheric pressure load acting between the first substrate and the second substrate and maintain a gap between the substrates, a plurality of spacers are disposed between the two substrates. A grid is provided between the first substrate and the second substrate, and a plurality of spacers are erected on the grid. A plurality of electron beam passage holes through which the electron beams emitted from the electron-emitting devices pass are formed in the grid (Patent Document 1).

In the SED, when displaying an image, an anode voltage is applied between the phosphor layer and the second substrate, and between the grid and the second substrate, and the electron beam emitted from the electron-emitting device is applied by the anode voltage. Accelerate and collide with the phosphor layer. As a result, the phosphor emits light and displays an image. In order to obtain practical display characteristics, it is necessary to use a phosphor similar to a normal cathode ray tube and set the anode voltage to several kV or more, preferably 5 kV or more.
JP 2002-082850 A

  In the SED having the above configuration, the gap between the first substrate and the second substrate is set to be relatively small, such as about 1 to 2 mm, from the viewpoint of resolution, grid characteristics, manufacturability, and the like. The gap between the grid and the second substrate is set smaller. In this case, it is inevitable that a strong electric field is formed in a small gap between the first substrate and the second substrate, and discharge (dielectric breakdown) between the two substrates becomes a problem.

  The grid provided between the first and second substrates is usually formed by forming an electron beam passage hole in a metal plate such as a 50Ni—Fe alloy. When such a metal plate is used, it becomes difficult to control the discharge current value flowing through the grid. For example, even when the surface of the grid is covered with an insulating layer having a thickness of 20 μm, dielectric breakdown occurs due to discharge, and a large current flows through the grid. The grid includes a feeding point for applying a voltage. For this reason, when a large current flows through the grid, a large current flows through the power feeding circuit through the power feeding point, which may damage the power feeding circuit.

  Such a discharge that leads to the occurrence of a defect is not allowed as a product. Therefore, in order to put SED into practical use, it must be configured so that damage due to discharge does not occur for a long period of time.

  The present invention has been made to solve such problems, and its purpose is to reduce the discharge current flowing in the grid to prevent deterioration and destruction of the circuit, and to improve the reliability and display quality. It is to provide an apparatus and a method for manufacturing the same.

In order to achieve the above object, a flat display device according to an aspect of the present invention includes a first substrate on which a phosphor screen and a metal back layer are formed, and is disposed to face the first substrate with a gap therebetween, and A second substrate provided with a plurality of electron emission sources for exciting the surface, and a spacer structure provided between the first and second substrates for supporting an atmospheric pressure load acting on the first and second substrates. Prepared,
The spacer structure is opposed to the first and second substrates and includes a grid having a plurality of electron beam passage holes opposed to the electron emission sources, and a plurality of standing structures on the surface of the grid. The grid is formed in a mesh shape having a plurality of metal wires and a plurality of glass wires extending perpendicular to the metal wires, and at least one of the end portions of the metal wires is Are electrically connected to each other.

  According to another aspect of the present invention, there is provided a method of manufacturing a flat display device, wherein a metal plate is etched to form a plurality of metal wires arranged in parallel with a predetermined gap therebetween, and the metal wires are made of glass. Covering, arranging a plurality of glass wires at a pixel pitch, superimposing the metal wires and frames on the arranged glass wires, firing and fastening the ends of the glass wires and the frames to grid And a spacer is formed on the glass wire of the grid.

  According to the present invention, it is possible to provide a flat panel display device with improved reliability and display quality, and a method for manufacturing the same, by suppressing the discharge current flowing through the grid to prevent circuit deterioration and breakdown.

Hereinafter, embodiments in which the present invention is applied to an SED as a flat display device will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 3, the SED includes a first substrate 10 and a second substrate 12 each made of a rectangular glass plate, and these substrates have a gap of about 1.0 to 2.0 mm. Corresponding arrangement. The first substrate 10 and the second substrate 12 are flat vacuum envelopes whose peripheral portions are joined to each other via a rectangular frame-shaped side wall 14 made of glass, and the inside is maintained at a high vacuum of about 10 ⁻⁴ Pa. 15 is constituted.

  A phosphor screen 16 that functions as a phosphor screen is formed on the inner surface of the first substrate 10. The phosphor screen 16 is configured by arranging phosphor layers R, G, and B that emit light in red, blue, and green, and a light shielding layer 11, and these phosphor layers are formed in stripes, dots, or rectangles. ing. On the phosphor screen 16, a metal back 17 and a getter film 19 made of aluminum or the like are sequentially formed.

  On the inner surface of the second substrate 12, a number of surface-conduction electron-emitting elements 18 that emit electron beams are provided as electron emission sources for exciting the phosphor layers R, G, and B of the phosphor screen 16. Yes. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. When the longitudinal direction of the first substrate 10 is the first direction X and the width direction orthogonal thereto is the second direction Y, the electron-emitting devices 18 are arranged at the first pixel pitch in the first direction X and in the second direction. They are arranged at the second pixel pitch. In the present embodiment, the second pixel pitch is set larger than the first pixel pitch.

  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 inner surface of the second substrate 12, a large number of wirings 21 for supplying a potential to the electron-emitting devices 18 are provided in a matrix shape, and end portions thereof are drawn out of the vacuum envelope 15. When the longitudinal direction of the first substrate 10 is the first direction X and the width direction orthogonal thereto is the second direction Y, the wiring 21 is a plurality of scanning wirings extending in parallel with each other along the first direction X. And signal wirings extending in parallel with each other along the second direction Y.

  The side wall 14 functioning as a bonding member is sealed to the peripheral edge of the first substrate 10 and the peripheral edge of the second substrate 12 by, for example, a sealing material 20 such as low-melting glass or low-melting metal. Are joined.

  As shown in FIGS. 2 to 5, the SED includes a spacer structure 22 disposed between the first substrate 10 and the second substrate 12. In the present embodiment, the spacer structure 22 includes a rectangular grid 24 disposed between the first and second substrates 10 and 12, a large number of columnar spacers integrally provided on both sides of the grid, It consists of

  More specifically, the grid 24 is formed in a rectangular shape in which the first direction X is the longitudinal direction and the second direction Y is the width direction. The grid 24 includes a rectangular frame 40 made of glass, a plurality of glass wires 42, and a plurality of metal wires 44 extending perpendicular to the glass wires, and is formed in a mesh shape. The glass wire 42 is formed in a prismatic or cylindrical shape having a diameter of 0.1 to 0.4 mm, and extends between the short sides of the frame body 40 along the first direction X. The glass lines 42 are arranged at a second pixel pitch along the second direction Y. Both ends of each glass wire 42 are integrally connected to the frame 40.

  The metal wire 44 is formed in a prismatic or cylindrical shape with a line width of 20 to 30 μm, and its surface is covered with glass as an insulating material. The plurality of metal lines 44 each extend between the long sides of the frame body 40 along the second direction Y, and are arranged at the first pixel pitch along the first direction X. These metal wires 44 are arranged so as to overlap the glass wires 42 and are fixed to the glass wires and the frame body 40. One end of the metal wire 44 is connected to a conductive line 46a extending between the short sides of the frame body 40 along the first direction X, and is electrically connected to each other via the conductive line 46a. Similarly, the other end of the metal wire 44 is connected to a conductive line 46b extending between the short sides of the frame body 40 along the first direction X, and is electrically connected to each other via the conductive line 46b. . The conductive lines 46a and 46b are each composed of a metal wire covered with glass.

  Thus, a mesh is formed by the plurality of glass wires 42 and metal wires 44 extending orthogonally to each other, and a large number of electron beam passage holes 26 are defined by regions surrounded by the glass wires and metal wires 44. The electron beam passage holes 26 are arranged at the same pitch as the electron-emitting devices 18 in the first direction and the second direction, respectively.

  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, and is arranged in parallel with these substrates. As shown in FIGS. 2, 3, and 5, on the first surface 24 a of the grid 24, a plurality of first spacers 30 a are integrally provided on the glass wire 42, and are aligned in the second direction Y, respectively. It is located between the electron beam passage holes 26. On the second surface 24 b of the grid 24, a plurality of second spacers 30 b are integrally provided on the glass wire 42, and are positioned between the electron beam passage holes 26 aligned in the second direction Y, respectively. The first and second spacers 30a and 30b are aligned with each other, and are formed integrally with the grid 24 with the grid 24 sandwiched from both sides.

  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. For example, each first spacer 30a has a substantially elliptical cross-sectional shape, the diameter of the proximal end located on the grid 24 side is about 0.3 mm × 2 mm, the diameter of the extended end is about 0.2 mm × 2 mm, The height is about 0.6 mm. Each of the second spacers 30b has a substantially elliptical cross-sectional shape, the diameter of the proximal end located on the grid 24 side is about 0.3 mm × 2 mm, the diameter of the extended end is about 0.2 mm × 2 mm, and the height. Is formed in about 0.8 mm.

  The spacer structure 22 configured as described above is disposed between the first substrate 10 and the second substrate 12. Each corner of the grid 24 is fixed to a support column 48 erected on the corner of the first substrate 12. A large number of electron beam passage apertures 26 formed in the grid 24 face the electron-emitting devices 18 and transmit the electron beams emitted from the corresponding electron-emitting devices 18.

  The tip of the first spacer 30 a is in contact with the inner surface of the first substrate 10 through the getter film 19, the metal back 17, and the light shielding layer 11 of the phosphor screen 16. The tip of the second spacer 30 b is in contact with the inner surface of the second substrate 12. Here, the tip of each second spacer 30 b is located on the wiring 21 provided on the inner surface of the second substrate 12. Thus, the first and second spacers 30a and 30b support the atmospheric pressure load acting on the first substrate 10 and the second substrate 12, and maintain the interval between these substrates at a predetermined value.

Next, the manufacturing method of SED comprised as mentioned above is demonstrated. First, a method for manufacturing the spacer structure 22 will be described.
First, a metal plate made of 50 wt% Ni—Fe alloy having a plate thickness of 0.1 mm is prepared, and the metal plate is etched to form a plurality of metal wires 44 each having a line width of 20 to 30 μm. Thereafter, the surface of each metal wire 44 is covered with 10 μm thick glass. A plurality of cylindrical or prismatic glass wires 42 each having a diameter of 0.1 to 0.4 mm are prepared and arranged in parallel with each other at a predetermined pitch. Subsequently, the rectangular frame 40 and the metal wire 44 are positioned and placed on the arranged glass wires 42, and the whole is fired at a predetermined temperature. Thereby, the glass wire 42, the frame body 40, and the metal wire 44 are integrated, and the grid 24 is formed.

  Next, a plurality of first and second spacers 30a and 30b are formed on the glass wire 42, respectively. In this case, a rectangular plate-like upper mold and lower mold having substantially the same dimensions as the grid 24 are prepared. The upper mold and the lower mold are formed in a flat plate shape using a transparent material that transmits ultraviolet rays, for example, transparent silicon, transparent polyethylene terephthalate, or the like. The upper mold has a flat abutting surface that abuts against the grid and a large number of bottomed spacer forming holes for molding the first spacer 30a. The spacer forming holes are opened in the contact surface of the upper mold, and are arranged at a predetermined interval. Similarly, the lower mold has a flat contact surface and a large number of bottomed spacer forming holes for forming the second spacer 30b. Each of the spacer forming holes is opened on the contact surface of the lower mold, and is arranged at a predetermined interval.

  Subsequently, the upper mold spacer forming hole and the lower mold spacer forming hole are filled with a spacer forming material. As the spacer forming material, a glass paste containing at least an ultraviolet curable binder (organic component) and a glass filler is used. The specific gravity and viscosity of the glass paste are appropriately selected.

  The upper mold is positioned and the contact surface is brought into close contact with the first surface 24 a of the grid 24 so that the spacer forming holes filled with the spacer forming material respectively face the glass wires 42. Similarly, the lower mold is positioned so that each spacer forming hole faces the glass wire 42, and the contact surface is brought into close contact with the second surface 24 b of the grid 24. Note that an adhesive may be applied in advance to the spacer standing position of the grid 24 by dispenser or printing. Thus, an assembly including the grid 24, the upper mold, and the lower mold is configured. In the assembly, the upper spacer formation hole and the lower spacer formation hole are arranged to face each other with the grid 24 interposed therebetween.

  Next, ultraviolet rays (UV) are irradiated from an ultraviolet lamp disposed outside the upper mold and the lower mold toward the upper mold and the lower mold. The ultraviolet rays irradiated from the ultraviolet lamp pass through the upper mold and the lower mold, and are irradiated to the filled spacer forming material. As a result, the spacer forming material is UV-cured while maintaining the tight adhesion of the assembly.

  Subsequently, the upper mold and the lower mold are released from the grid 24 so that the cured spacer forming material remains on the grid 24. Thereafter, the grid 24 provided with the spacer forming material is heat-treated in a heating furnace, the binder is removed from the spacer forming material, and then the spacer forming material is subjected to main baking at about 500 to 550 ° C. for 30 minutes to 1 hour. Thereby, the spacer structure 22 in which the first and second spacers 30a and 30b are formed on the grid 24 is obtained.

  On the other hand, in the manufacture of the SED, the first substrate 10 provided with the phosphor screen 16 and the metal back 17 in advance, the second substrate on which the electron-emitting device 18 and the wiring 21 are provided and the side wall 14 is joined. 12 are prepared. Subsequently, the spacer structure 22 obtained as described above is positioned on the second substrate 12. In this state, the first substrate 10, the second substrate 12, and the spacer structure 22 are arranged in the vacuum chamber, the inside of the vacuum chamber is evacuated, and then the first substrate is bonded to the second substrate via the side wall 14. . Thereby, SED provided with the spacer structure 22 is manufactured.

  According to the SED configured as described above, the grid 24 is formed in a mesh shape by the glass wire 42 and the metal wire 44. Therefore, compared with the grid formed only by the metal plate, the cross-sectional area of the metal part in a grid reduces, and the electrical resistance value of a grid increases in connection with this. Therefore, even when a discharge occurs, the discharge current flowing through the grid 24 and the feeding point of the grid can be reduced to about 1/100 compared with a grid formed by only a metal plate. As a result, when a discharge occurs, the power supply circuit is prevented from being deteriorated and damaged, and an SED having improved reliability and display quality and a method for manufacturing the same are obtained.

  In the above-described embodiment, the spacer structure 22 is configured to integrally include the first and second spacers and the grid, but the second spacer 30b may be formed on the second substrate 12. The spacer structure may include only the grid 24 and the second spacer, and the grid may be in contact with the first substrate 10.

  As shown in FIG. 6, according to the SED according to the second embodiment of the present invention, the spacer structure 22 includes a grid 24 and a number of columnar spacers that are integrally provided on only one surface of the grid. 30. 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, and is arranged in parallel with these substrates. As in the first embodiment described above, the grid 24 includes a frame, a plurality of glass wires 42, and a plurality of metal wires 44, and is formed in a mesh shape. The grid 24 has a large number of electron beam passage holes 26, and these electron beam passage holes 26 are arranged to face the electron-emitting devices 18.

  The grid 24 is provided with the first surface 24 a in surface contact with the inner surface of the first substrate 10 via the getter film 19, the metal back 17, and the phosphor screen 16. Electron beam passage holes 26 provided in the grid 24 are opposed to the phosphor layers R, G, and B of the phosphor screen 16. Thereby, each electron-emitting device 18 is opposed to the corresponding phosphor layer through the electron beam passage hole 26.

  On the second surface 24 b of the grid 24, a plurality of spacers 30 are erected integrally on the glass wire 42, and are respectively positioned between the electron beam passage holes 26. The extended end of each spacer 30 is in contact with the inner surface of the second substrate 12, here, the wiring 21 provided on the inner surface of the second substrate 12. Each of the spacers 30 is formed in a tapered shape with a diameter decreasing from the grid 24 side toward the extending end. For example, the spacer 30 is formed with a height of about 1.4 mm. The cross section of the spacer 30 along the direction parallel to the grid surface is substantially elliptical.

  In the spacer structure 22 configured as described above, the grid 24 is in surface contact with the first substrate 10, and the extended end of the spacer 30 is in contact with the inner surface of the second substrate 12. The atmospheric pressure load is supported, and the distance between the substrates is maintained at a predetermined value.

  In the second embodiment, other configurations are the same as those of the first embodiment described above, and the same reference numerals are given to the same portions, and detailed description thereof is omitted. The SED and its spacer structure according to the second embodiment can be manufactured by a manufacturing method similar to the manufacturing method according to the above-described embodiment. In the second embodiment, the same operational effects as those of the first embodiment described above can be obtained.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  The diameter and height of the spacer, the dimensions and materials of the other components are not limited to the above-described embodiment, and can be appropriately selected as necessary. The present invention is not limited to the one using a surface conduction electron-emitting device as an electron source, but can be applied to a flat panel display using other electron sources such as a field emission type and a carbon nanotube.

The perspective view which shows SED which concerns on 1st Embodiment of this invention. The perspective view of said SED which cuts and shows a part. FIG. 2 is a cross-sectional view of the SED along line AA in FIG. 1. The perspective view which shows the grid in the spacer structure of said SED. The perspective view which expands and shows a part of said spacer structure. Sectional drawing which shows SED which concerns on 2nd Embodiment of this 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-emitting device, 22 ... spacer structure,
24 ... Grid, 26 ... Electron beam passage hole, 30 ... Spacer,
30a ... 1st spacer, 30b ... 2nd spacer, 40 ... Frame body,
42 ... Glass wire, 44 ... Metal wire, 46a, 46b ... Conductive wire

Claims (9)

A first substrate on which a phosphor screen and a metal back layer are formed;
A second substrate disposed opposite to the first substrate and provided with a plurality of electron emission sources for exciting the phosphor screen;
A spacer structure provided between the first and second substrates and supporting an atmospheric pressure load acting on the first and second substrates;
The spacer structure is opposed to the first and second substrates and includes a grid having a plurality of electron beam passage holes opposed to the electron emission sources, and a plurality of standing structures on the surface of the grid. A spacer, and
The grid includes a plurality of metal wires and a plurality of glass wires extending across the metal wires and is formed in a mesh shape, and at least one of the end portions of the metal wires is electrically connected to each other. Flat display device.   The grid is formed in a rectangular shape and has a first direction extending in the longitudinal direction and a second direction extending in the width direction, and the plurality of metal lines each extend in parallel with the Y direction. Flat display device.   The flat display device according to claim 1, wherein each metal wire is coated with glass.   The flat display device according to any one of claims 1 to 3, wherein the grid includes a rectangular frame, and both ends of the glass wire are formed integrally with the frame.   The flat display device according to claim 1, wherein the spacer is erected on a glass wire of the grid.   The grid has a first surface facing the first substrate and a second surface facing the second substrate, and the spacer is a plurality of first surfaces erected on the first surface. The flat display device according to claim 1, comprising a spacer and a plurality of second spacers erected on the second surface.   The grid has a first surface in contact with the first substrate, and a second surface facing the second substrate with a gap, and the spacer is erected on the second surface. The flat display device according to claim 1, wherein the flat display device has a tip portion in contact with the second substrate.   The flat display device according to claim 1, wherein the spacer is a columnar spacer. In the manufacturing method of the flat display device according to any one of claims 1 to 8,
By etching the metal plate, a plurality of metal wires arranged in parallel with a predetermined gap from each other are formed,
Coating the metal wire with glass;
Arrange multiple glass wires at pixel pitch,
After superimposing the metal wire and the frame on the arranged glass wire, firing and fastening the end of the glass wire and the frame to form a grid,
A method of manufacturing a flat display device, wherein a spacer is formed on a glass wire of the grid.

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