JP2005005079A - Self-luminous flat display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-luminous flat display device capable of providing sufficient electron emission by raising nanotubes in a contactless manner. <P>SOLUTION: A cathode electrode is formed by printing of paste with nanotubes mixed; multiple minute craters 1301 are formed by spraying dry ice to a surface of an electron source print film 100; the nanotubes 103 in the minute craters and in the vicinities thereof are raised; and thereby a geometric arrangement wherein a raising rate of the nanotubes is increased as compared with parts separated from the minute craters is formed to realize efficient electric field concentration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device using electron emission into a vacuum, and in particular, a rear panel having a cathode electrode having an electron source composed of nanotubes and a gate electrode for controlling the amount of electrons emitted from the electron source. The present invention relates to a self-luminous flat panel display device including a plurality of color phosphor layers that emit light by excitation of electrons extracted from the front panel and a front panel having an anode electrode, and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, a color cathode ray tube has been widely used as a display device excellent in high luminance and high definition. However, with the recent improvement in image quality of information processing devices and television broadcasting, there is an increasing demand for flat display devices that have high brightness and high definition characteristics, light weight, and space saving.
[0003]
As typical examples, liquid crystal display devices, plasma display devices and the like have been put into practical use. In particular, it is possible to increase the brightness, such as an electron emission display device using electron emission from an electron source to a vacuum, or a field emission display device, an organic EL display characterized by low power consumption, etc. Various types of panel-type display devices will soon be put into practical use. A plasma display device, an electron emission display device, or an organic EL display device that does not require an auxiliary illumination light source is referred to as a self-luminous flat display device.
[0004]
Among such flat display devices, the field emission display device includes C.I. A. Spindt et al., Conical electron emission structure, metal-insulator-metal (MIM) type electron emission structure, electron emission structure using electron emission phenomenon due to quantum tunnel effect (surface Also known are those having a conduction electron source, and those utilizing the electron emission phenomenon of diamond films, graphite films, nanotubes typified by carbon nanotubes, and the like.
[0005]
A field emission display device, which is an example of a self-luminous flat display device, has a back panel in which a field emission electron source and a gate electrode as a control electrode are formed on the inner surface, and a plurality of colors on the inner surface facing the rear panel. The front panel provided with the phosphor layer and the anode electrode (anode) is sealed by inserting a sealing frame at the inner periphery of the front panel, and the interior formed by the rear panel, the front panel and the sealing frame is vacuumed Configured. The rear panel extends in a first direction and extends in a second direction intersecting with the first direction on a rear substrate preferably made of glass or alumina, and is arranged in parallel in the first direction. A plurality of cathode wirings having an electron source and a gate electrode extending in the second direction and arranged in parallel in the first direction. Then, the amount of electrons emitted from the electron source (including emission on / off) is controlled by the potential difference between the cathode electrode and the gate electrode.
[0006]
The front panel has a phosphor layer and an anode electrode on a front substrate made of a light-transmitting material such as glass. The sealing frame is fixed to the inner peripheral edge of the back panel and the front panel with an adhesive such as frit glass. The degree of vacuum inside the back panel, the front panel and the sealing frame is, for example, 10 ^-5 -10 ^-7 Torr. In the case where the display surface size is large, a gap holding member (spacer) is interposed between the rear panel and the front panel, and the gap between the two substrates is held at a predetermined interval.
[0007]
In addition, there are many reports such as “Non-patent Document 1” as a disclosure of the prior art relating to a self-luminous flat panel display using carbon nanotubes, which are typical examples of nanotubes, as an electron source.
[0008]
[Non-Patent Document 1]
SID 99 Digest pp. 1134-1137
[0009]
[Problems to be solved by the invention]
Many electron-emitting devices using nanotubes such as carbon nanotubes and self-luminous flat panel displays using the same have been reported. “Non-Patent Document 1” discloses an example in which a self-luminous flat panel display device having a nominal size of 4.5 inches is produced using a carbon nanotube electron source formed by printing. In such a self-luminous flat panel display using an electron source formed by printing nanotubes, the number of nanotubes in a raised state is extremely small because the nanotubes are generally lying on the printed surface. Therefore, an electric field for emitting electrons is not effectively applied to the nanotube, and it is difficult to obtain sufficient electron emission.
[0010]
Conventionally, a method of mechanically polishing the printed surface is often used in order to raise the nanotube lying on the printed surface. However, the surface of the printed surface has irregularities, and it is difficult to raise the nanotubes in the recessed portion by the above polishing. In a self-luminous flat panel display using nanotubes as an electron source, it is necessary to provide a gate electrode for performing electron extraction control on the electron source. Therefore, the nanotube is generally present at the bottom of the hollow structure below the gate electrode, and it is difficult to polish and brush the nanotube in a non-contact manner after such a structure is formed.
[0011]
An object of the present invention is to provide a self-luminous flat panel display device and a method for manufacturing the same which can obtain sufficient electron emission by raising nanotubes in a non-contact manner.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a self-luminous flat panel display device according to the present invention is provided on a rear substrate in parallel with a second direction extending in a first direction and intersecting the first direction. A plurality of cathode electrodes having a plurality of electron sources, and the cathode electrodes extend in the second direction through an insulating layer and are arranged in parallel in the first direction to take out electrons from the electron source. A back panel comprising a plurality of gate electrodes to be controlled and constituting a display region with a large number of pixels formed at intersections of the cathode electrode and the gate electrode;
A plurality of color phosphor layers that emit light by excitation of electrons extracted from the electron source in the display area of the back panel, and a front panel having an anode electrode,
The cathode electrode is formed by printing a paste in which nanotubes are mixed, and has a large number of micro craters on the printed surface, and the brushing rate of the nanotubes in the micro crater and the vicinity thereof is determined from a portion away from the micro crater. It is also characterized by a higher height.
[0013]
In the self-luminous flat display device of the present invention, the diameter and depth of the micro craters are randomly distributed, and the nanotubes are carbon nanotubes.
[0014]
The method for manufacturing a self-luminous flat panel display according to the present invention includes the step of forming the cathode electrode by printing a paste in which nanotubes, conductive particles, and a fixing agent are mixed;
Baking and curing the printed paste; and
The method includes a step of spraying solid fine particles of a substance that is solid at low temperature and vaporizes at room temperature on the cured printed surface to form a large number of microcraters and raise the nanotubes.
[0015]
Further, the present invention is characterized in that the solid fine particles are sprayed from a direction perpendicular to or oblique to the printing surface, or the solid fine particles are selectively sprayed only on the paste in the pixel portion. .
[0016]
As the solid fine particles, dry ice is preferably used, but other similar materials can be used, and the nanotubes are preferably carbon nanotubes.
[0017]
Note that the present invention is not limited to the above-described configuration and the configuration described in the embodiments described later, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of examples using carbon nanotubes as electron sources. FIG. 1 is a schematic view for explaining a first embodiment of a method for raising carbon nanotubes constituting an electron source. First, a paste obtained by mixing the carbon nanotubes 103, the metal particles 102 as conductive particles, and the fixing agent 104 is applied on a substrate (front substrate) suitable for glass by screen printing. Thereafter, the electron source printed film 100 is obtained by baking. Dry ice fine particles 106 are sprayed from above the electron source printing film 100 by the spray nozzle 105. The nozzle 105 is moved along the surface of the electron source printing film 100 as indicated by an arrow, and sprays dry ice fine particles 106 on a required region.
[0019]
As a result of this treatment, many of the carbon nanotubes 103 are released from the bonding with the fixing agent 104, and once pressed, the other end rebounds and is often raised from the substrate surface. Further, as will be described later, a crater is formed on the electron source printing film 100 by spraying the fine particles 106 of dry ice, the carbon nanotubes 203 are exposed in and near the crater, and the carbon nanotubes around the crater are Raised state.
[0020]
FIG. 2 is a schematic diagram for explaining a second embodiment of a method for raising carbon nanotubes constituting an electron source. In the present embodiment, similarly to the previous embodiment, a paste obtained by mixing the carbon nanotubes 103, the metal particles 102 as conductive particles, and the fixing agent 104 is applied to the back substrate 101 by screen printing. Thereafter, the electron source printed film 100 is obtained by baking. Dry ice fine particles 106 are sprayed from the obliquely upper side of the electron source printing film 100 by the spray nozzle 105. The nozzle 105 is moved along the surface of the electron source printing film 100 as indicated by an arrow, and sprays dry ice fine particles 106 on a required region.
[0021]
As a result of this treatment, many of the carbon nanotubes 103 are released from the bonding with the fixing agent 104, and once pressed, the other end rebounds and is often raised from the substrate surface. Further, by spraying the fine particles 106 of dry ice obliquely, a crater, which will be described later, is formed longer in the moving direction of the nozzle 105 on the electron source printing film 100, and the carbon nanotubes in the electron source printing film 100 are raised more effectively. can do. The carbon nanotubes 103 are exposed in and near the crater, and the carbon nanotubes around the crater are raised.
[0022]
FIG. 3 is a schematic diagram for explaining the outline of the dry ice spraying apparatus used in the manufacturing method of the present invention. Reference numeral 301 denotes an apparatus main body, and a liquefied carbon dioxide source 304 and a carrier gas source 305 are connected to the apparatus main body 301 by introduction pipes 304A and 305A, respectively. The apparatus main body 301 depressurizes the liquefied carbon dioxide gas introduced from the liquefied carbon dioxide gas source 304 to form dry ice fine particles, and supplies the dry ice fine particles together with the carrier gas from the carrier gas source 305 to the nozzle 105 via the outlet pipe 302A. By adjusting the pressures of the liquefied carbon dioxide gas and the carrier gas, the speed, density and particle size of the dry ice fine particles 106 ejected from the nozzle 105 are controlled.
[0023]
FIG. 4 is an explanatory view of an example of the shape of a nozzle used in the manufacturing method of the present invention. 4A shows a side view and FIG. 4B shows the shape of the injection port. In this example, the nozzle 105 has a cylindrical shape, and the shape 302 of the injection port is a circular port.
[0024]
FIG. 5 is an explanatory view of another example of the shape of the nozzle used in the manufacturing method of the present invention. FIG. 5A shows a side view, and FIG. 5B shows the shape of the injection port. In this example, the nozzle 105 has a flat box shape, and the shape of the injection port 302 is a long rectangle. Dry ice fine particles can be efficiently ejected by setting the longitudinal size of the ejection port 302 to be approximately the same as the width of the rear substrate. The shape of the nozzle can be arbitrarily selected according to the size and shape of the carbon nanotube.
[0025]
6A and 6B are schematic views for explaining the shape of the surface of the electron source of the carbon nanotube after the raising treatment with dry ice fine particles, FIG. 6A is a top view, and FIG. 6B is an A- in FIG. Sectional drawing along an A 'line is shown. The diameter of the dry ice fine particles is about 0.1 μm to several tens of μm. A large number of craters 1301 are formed on the surface of the carbon nanotube electron source printing film 100 by spraying the dry ice fine particles. The size of the depression of the crater 1301 is about 0.1 μm to several tens of μm corresponding to the diameter of the dry ice fine particles.
[0026]
The carbon nanotubes 103 lying in the electron source printing film 100 in the formation process of the crater 1301 are partly removed of the sticking agent by the collision of the dry ice fine particles, and the carbon nanotubes embedded in the sticking agent are electron source printed. It is exposed from the film 100 and raised by the propellant gas. FIG. 6B shows the state. The raised portions have a higher raising rate in the crater 1301 and in the vicinity thereof than other portions, that is, a geometrical arrangement that protrudes from a portion away from the minute crater. Therefore, a large number of projection groups are formed in the region of the electron source printing film 100, and the electric field concentration effect is increased. As a result, sufficient electron emission can be obtained.
[0027]
Next, a first embodiment of the self-luminous flat panel display according to the present invention will be described with reference to FIGS. FIG. 7 is an exploded perspective view showing the entire structure of the first embodiment of the self-luminous flat display device according to the present invention as seen obliquely from above. FIG. 8 is a schematic view seen from obliquely below, explaining the overall structure of the self-luminous flat display device of FIG.
[0028]
7 and 8, the self-luminous flat display device of this embodiment is configured by sealing and integrating the back panel 1 and the front panel 2 with a sealing frame 3. The back panel 1 has a large number of cathode electrodes arranged in parallel in a second direction extending in a first direction as an electron emission / control structure on the inner surface of a back substrate 601 preferably made of glass. 701 and a number of gate electrodes 702 extending in the second direction and extending in the first direction. A video signal (denoted as a scanning signal in the figure) is applied to the cathode electrode 701, and a selection signal (denoted as a gate signal in the figure) is applied to the gate electrode 702.
[0029]
The front substrate 603 constituting the front panel 2 is preferably made of transparent glass, and a plurality of (herein, three colors of red (R), green (G), and blue (B)) phosphor layers 800 are provided on the inner surface thereof. An anode electrode 602 is formed on the entire surface by applying aluminum in a thickness of several tens to several hundreds nm as a transparent conductive film. An acceleration voltage is applied to the anode electrode 602. The phosphor layer 800 is not limited to a stripe shape as illustrated, and may be a dot shape for each color. The sealing frame 3 has a function of maintaining the gap between the opposing surfaces at a predetermined value as well as a function of maintaining the inside of the bonded back panel 1 and front panel 2 in a vacuum state. When the screen size is large, a gap between the opposing surfaces is predetermined by interposing a columnar spacer made of glass beads, plastic beads, or a resist formed by photolithography between both panels sealed with the sealing frame 3. Holding on to the value is done. The sealing frame 3 is also preferably made of glass.
[0030]
FIG. 9 is a schematic explanatory view of a configuration example of a back panel constituting the self-luminous flat display device of the present invention, FIG. 9 (a) is a plan view, and FIG. 9 (b) is a diagram of FIG. 9 (a). A configuration of one pixel which is a main part is shown. In the display region 700 of the back substrate 601, the cathode electrode 701 and the gate electrode 702 are arranged in a matrix. The cathode electrode 701 and the gate electrode 702 are electrically insulated by an insulating layer (not shown), and as shown in FIG. 9B, an electron source (here, carbon nanotube) 703 formed of carbon nanotubes at each intersection. have. The electron source 703 is formed on the cathode electrode 701 and exposed from a control opening (described later) provided in the gate electrode 702.
[0031]
FIG. 10 is a schematic explanatory view of a configuration example of a front panel constituting the self-luminous flat display device of the present invention, FIG. 10 (a) is a plan view, and FIG. 10 (b) is a diagram of FIG. 10 (a). The example of an arrangement | sequence of the phosphor layer which is the principal part is shown. In addition, although the above-mentioned anode electrode is formed on the upper surface of the phosphor layer, the illustration is omitted. The front panel 2 is an image observation surface, and the front substrate 603 is preferably glass. The inner surface of the front substrate 603 has three-color phosphors 801 (red), 802 (green), and 803 (blue) that are repeatedly arranged in a stripe pattern, and is shielded from light at the boundaries between the phosphors 801, 802, and 803. A layer or black matrix 804 is disposed. Each of the phosphors 801, 802, and 803 is arranged to face one pixel (here, corresponding to a color sub-pixel) having the above-described electron source, that is, each intersection of the cathode electrode and the gate electrode. The phosphor layer composed of these phosphors 801, 802, and 803 and the black matrix 804 is formed as follows.
[0032]
First, the black matrix 804 is formed on the front substrate 603 by a known lift-off method. Next, phosphors of three colors of red (R), green (G), and blue (B) are sequentially formed so that the phosphors are partitioned by the black matrix 804 using the same known slurry method. The above-described anode electrode is formed over it.
[0033]
The front panel 2 manufactured in this way is positioned with respect to the back panel 1 with the electron source and the phosphor, overlapped via the sealing frame 3, and bonded with frit glass. The frit glass is applied to one or both of the opposing surfaces of the front panel 2, the back panel 1, and the sealing frame 3, heated at 450 ° C., and cured by a subsequent temperature decrease. The internal space formed by both panels and the sealing frame is evacuated from an exhaust pipe (not shown), and then the exhaust pipe is sealed. The exhaust pipe is preferably provided on a part of the back substrate 601 or a part of the sealing frame 3. A desired image (image) can be displayed by applying a video signal to the cathode electrode, a control signal to the gate electrode, and an anode voltage (anode voltage: high voltage) to the anode electrode.
[0034]
Next, a first embodiment of the detailed structure of the back panel will be described with reference to FIGS. FIG. 11 is a plan view schematically illustrating the main structure of the back panel, and shows a 2 × 2 pixel portion. 12 is a sectional view taken along the line AA ′ in FIG. 11, and FIG. 13 is a sectional view taken along the line BB ′ in FIG. 11 to 13, a cathode electrode stripe 901 having a thickness of 0.2 to 10 μm and a width of 300 μm is formed on the surface of a rear substrate 909 made of glass (corresponding to reference numeral 601 in FIGS. 7 and 8). , Corresponding to reference numeral 701 in FIG. 8) is formed at intervals of 60 μm. Next, an insulating layer 905 is formed so as to cover the cathode electrode stripe 901. The insulating layer 905 has a thickness of 1 to 50 μm. An insulating layer opening 906 having a diameter of 1 to 50 μm is provided at a pixel portion of the insulating layer, that is, at an intersection with a gate electrode stripe described later.
[0035]
After the insulating layer 905 is fired, 2400 gate electrode stripes 902 (corresponding to reference numeral 702 in FIGS. 7 and 8) having a thickness of 0.2 to 10 μm, a width of 90 μm, and an interval of 30 μm are formed thereon. . A control opening 903 having a diameter of 1 to 50 μm is provided at the intersection of the cathode electrode stripe 901 and the gate electrode stripe 902. The gate electrode stripe 902 is coaxial with the insulating layer opening 906 of the insulating layer 905 and the control opening 903 of the gate electrode stripe 902 at the intersection with the cathode electrode stripe 901. The stripe 901 is provided with an electron source of carbon nanotubes.
[0036]
A self-luminous flat display device was manufactured by superimposing the above-mentioned front panel on the back panel having the electron emission / control structure thus configured, and sealing it with a sealing frame. Then, a scanning signal (video signal) is input to the cathode electrode stripe 901, a gate signal (control signal) is input to the gate electrode stripe 902, and an accelerating voltage is applied to the anode electrode of the front panel to display an image that uniformly emits light. I was able to.
[0037]
Next, a first embodiment of a process for forming an electron source on the back substrate will be described with reference to FIGS. 14 to 17 are explanatory views of a process for forming an electron source on the back substrate in the first embodiment of the present invention. 14A to 17A are top views of the electron source portion, FIG. 14B is a cross-sectional view taken along the line AA ′ of each figure, and FIG. 17C is FIG. It is sectional drawing which followed the BB 'line | wire disconnection.
[0038]
First, as shown in FIG. 14, 600 cathode electrode stripes 1001 (corresponding to reference numeral 901 in FIG. 12) having a width of 300 μm and an interval of 60 μm are formed on the front substrate 1009 (corresponding to reference numeral 909 in FIG. 12). To do. The cathode electrode stripe 1001 is formed by applying a conductive paste containing carbon nanotubes by screen printing. Its thickness is 1 μm. Next, as shown in FIG. 15, after the photosensitive dielectric paste is screen-printed on the entire surface, an insulating layer opening 1003 (corresponding to the insulating layer opening 906 in FIG. 12) is formed as an electron source opening by a normal photolithography process. Form. This is baked at 550 ° C. for 30 minutes in the atmosphere to form an insulating layer 1005 (corresponding to the insulating layer opening 905 in FIG. 12). The thickness of the insulating layer 1005 is 10 μm.
[0039]
As shown in FIG. 16, a photosensitive silver paste is screen printed on the entire surface. The gate electrode stripe 1002 shown in FIG. 17 (corresponding to the gate electrode stripe 902 in FIG. 12) is formed by a normal photolithography process, and the gate electrode stripe is obtained by baking at 550 ° C. for 30 minutes in the atmosphere. . The width of the gate electrode stripe 1002 is 90 μm and the interval is 30 μm, and 2400 of them are formed. The gate electrode stripe 1002 has a thickness of 5 μm, and a control opening having the same size or a slightly larger size is formed in the same portion as the opening of the insulating layer.
[0040]
Finally, dry ice fine particles were sprayed on the surface of the electron source printed film to raise carbon nanotubes. The dry ice fine particles may be sprayed by any of the methods shown in FIGS. When the nozzle shown in FIG. 4 is used, the nozzle and the back substrate are sprayed over the entire substrate while being relatively moved. When the nozzle shown in FIG. 5 is used, the nozzle and the back substrate are sprayed while moving in one direction. You may provide the mechanism which removes the dust (it arises from an electron source printing film) generated when spraying dry ice fine particles.
[0041]
In this embodiment, the cathode electrode stripe 1001 and the gate electrode stripe 1002 are formed of a specific metal. However, any metal or conductive material may be used as long as it has necessary electrical conductivity. . In this embodiment, the gate electrode stripe is manufactured by using the photolithography method, but other methods such as a screen printing method can also be used. Further, in this embodiment, carbon nanotubes are used as the electron source. However, the carbon nanotubes may be single wall, multi wall, mixed materials thereof, or nanotubes made of other materials other than carbon.
[0042]
In this embodiment, a geometrical arrangement in which the electric field is efficiently concentrated on the carbon nanotubes can be realized by the raising effect of the carbon nanotubes by spraying the dry ice fine particles, so that the in-plane with a low electric field of 1 V / μm or less. And uniform electron emission characteristics can be obtained. As a result, the average emission site density in all emission regions of each pixel is 1 million / cm. ² Or more, 10 million pieces / cm ² This is possible. Thereby, the luminance variation between adjacent pixels could be reduced to 1% or less.
[0043]
Next, a second embodiment of the detailed structure of the back panel will be described with reference to FIGS. FIG. 18 is a plan view schematically illustrating the main structure of the back panel of the self-luminous flat display device of the present invention, and shows a 2 × 2 pixel portion. 19 is a cross-sectional view taken along line AA ′ in FIG. 18, and FIG. 20 is a cross-sectional view taken along line BB ′ in FIG. 18 to 20, a striped cathode electrode having a thickness of 0.2 to 10 μm and a width of 300 μm on the surface of a back substrate 1109 (corresponding to reference numeral 909 in FIGS. 12 and 13) preferably made of glass. 600 pieces of 1101 (corresponding to reference numeral 901 in FIG. 11) are formed at an interval of 60 μm. Next, an insulating layer 1105 (corresponding to reference numeral 905 in FIG. 12) is formed so as to cover the cathode electrode 1101. The insulating layer 905 has a thickness of 1 to 50 μm. An insulating layer opening 1103 having a diameter of 1 to 50 μm is provided at a pixel portion of this insulating layer, that is, at an intersection with a gate electrode stripe described later.
[0044]
After the insulating layer 1103 is baked, 2400 stripe-shaped gate electrodes 1102 (corresponding to reference numeral 1102 in FIG. 13) having a thickness of 0.2 to 10 μm, a width of 90 μm, and an interval of 30 μm are formed thereon. A control opening 1104 having a diameter of 1 to 50 μm is provided at the intersection of the cathode electrode 1101 and the gate electrode 1102. Note that the insulating layer opening 1103 of the insulating layer 1103 and the control opening 1104 of the gate electrode 1102 are coaxial with the gate electrode 1102 at the intersection with the cathode electrode 1101. A nanotube electron source 1106 is provided.
[0045]
A self-luminous flat display device was manufactured by superimposing the above-mentioned front panel on the back panel having the electron emission / control structure thus configured, and sealing it with a sealing frame. Then, a scanning signal (video signal) is input to the cathode electrode 1101, a gate signal (control signal) is input to the gate electrode 1102, and an acceleration voltage is applied to the anode electrode of the front panel to display an image that emits light uniformly. I was able to.
[0046]
Next, a second embodiment of the process for forming the electron source on the back substrate will be described with reference to FIGS. 21 to 24 are explanatory views of a process for forming an electron source on the back substrate according to the second embodiment of the present invention. 21A to 24A are top views of the electron source portion, FIG. 21B is a cross-sectional view taken along the line AA ′ in FIGS. 21A and 24C, and FIG. It is sectional drawing which followed the BB 'line | wire disconnection.
[0047]
First, as shown in FIG. 21, a cathode electrode 1201 (corresponding to reference numeral 1101 in FIGS. 19 and 20) having a width of 300 μm and an interval of 60 μm on the front substrate 1209 (corresponding to reference numeral 1109 in FIGS. 19 and 20). ) Is formed. The cathode electrode 1201 is applied by screen printing of a photosensitive silver paste. Its thickness is 1 μm. Next, as shown in FIG. 22, the insulating layer 1205 is formed by screen printing. An insulating layer opening 1203 that becomes an electron source opening is formed by an ordinary photolithography process. This is baked at 550 ° C. for 30 minutes in the air to form the insulating layer 1205. The thickness of the insulating layer 1105 is 10 μm.
[0048]
As shown in FIG. 23, a photosensitive silver paste is screen printed on the entire surface. The gate electrode 1202 shown in FIG. 24 is formed by a normal photolithography process, and baking is performed in the atmosphere at 550 ° C. for 30 minutes to obtain the gate electrode. The width of the gate electrode 1202 is 90 μm, and the interval is 30 μm. The gate electrode 1202 has a thickness of 5 μm, and a control opening having the same size or a slightly larger size is formed in the same portion as the opening of the insulating layer. Finally, an ink containing carbon nanotubes was applied to the bottom of the opening of the insulating layer by an inkjet method to form an electron source 1206.
[0049]
Then, dry ice fine particles were sprayed on the surface of the electron source printed film to raise carbon nanotubes. The dry ice fine particles may be sprayed by any of the methods shown in FIGS. When the nozzle shown in FIG. 4 is used, the nozzle and the back substrate are sprayed over the entire substrate while being relatively moved. When the nozzle shown in FIG. 5 is used, the nozzle and the back substrate are sprayed while moving in one direction. You may provide the mechanism which removes the dust (it arises from an electron source printing film) generated when spraying dry ice fine particles.
[0050]
In this embodiment, the cathode electrode 1201 and the gate electrode 1202 are formed of a specific metal. However, any metal or conductive material may be used as long as it has necessary electrical conductivity. In this embodiment, the gate electrode stripe is manufactured by using the photolithography method, but other methods such as a screen printing method can also be used. Furthermore, in this embodiment, the ink containing carbon nanotubes is applied by the ink jet method, but it may be applied by using another application method such as screen printing. Further, the carbon nanotube may be a single wall, a multi wall, a mixed material thereof, or a nanotube made of a material other than carbon.
[0051]
In this embodiment, a geometrical arrangement in which the electric field is efficiently concentrated on the carbon nanotubes can be realized by the raising effect of the carbon nanotubes by spraying the dry ice fine particles, so that the in-plane with a low electric field of 1 V / μm or less. And uniform electron emission characteristics can be obtained. As a result, the average emission site density in all emission regions of each pixel is 1 million / cm. ² Or more, 10 million pieces / cm ² This is possible. Thereby, the luminance variation between adjacent pixels could be reduced to 1% or less.
[0052]
【The invention's effect】
As described above, according to the present invention, carbon nanotubes are made efficient by blowing a solid fine particle of a substance that is solid at room temperature such as deai ice and evaporating at room temperature to form a large number of micro craters and raising the nanotubes. A geometrical arrangement in which the electric field is well concentrated can be realized, and a self-luminous flat panel display device having a low electric field of 1 V / μm or less and uniform in-plane electron emission characteristics can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic view for explaining a first embodiment of the present invention of a method for raising carbon nanotubes constituting an electron source.
FIG. 2 is a schematic view for explaining a second embodiment of the present invention of a method for raising carbon nanotubes constituting an electron source.
FIG. 3 is a schematic view for explaining an outline of a dry ice jetting apparatus used in the method for manufacturing a self-luminous flat panel display device of the present invention.
FIG. 4 is an explanatory diagram showing an example of the shape of a nozzle used in the method for manufacturing a self-luminous flat panel display device of the present invention.
FIG. 5 is an explanatory view of another example of the shape of a nozzle used in the method for manufacturing a self-luminous flat panel display device of the present invention.
FIG. 6 is a schematic diagram for explaining the shape of the surface of the electron source of the carbon nanotube after the raising treatment with dry ice fine particles.
FIG. 7 is an exploded perspective view showing the entire structure of the first embodiment of the self-luminous flat display device according to the present invention as seen obliquely from above.
FIG. 8 is a schematic view seen from obliquely below explaining the overall structure of the self-luminous flat display device of FIG. 7;
FIG. 9 is a schematic explanatory view of a configuration example of a back panel constituting the self-luminous flat display device of the present invention.
FIG. 10 is a schematic explanatory view of a configuration example of a front panel constituting the self-luminous flat display device of the present invention.
FIG. 11 is a plan view schematically illustrating the main structure of the back panel.
12 is a cross-sectional view taken along line AA ′ of FIG.
13 is a cross-sectional view taken along the line BB ′ of FIG.
FIG. 14 is an explanatory diagram of a process for forming an electron source on a back substrate in the first embodiment of the present invention.
15 is an explanatory diagram of a process following FIG. 14 for forming an electron source on the back substrate in the first embodiment of the invention. FIG.
16 is an explanatory diagram of a process following FIG. 15 for forming an electron source on the back substrate in the first embodiment of the invention. FIG.
FIG. 17 is an explanatory diagram of a process following FIG. 16 for forming an electron source on the back substrate in the first embodiment of the invention.
FIG. 18 is a plan view schematically illustrating the main structure of the rear panel of the self-luminous flat display device of the present invention.
19 is a cross-sectional view taken along line AA ′ of FIG.
20 is a cross-sectional view taken along line BB ′ of FIG.
FIG. 21 is an explanatory diagram of a process for forming an electron source on a back substrate according to the second embodiment of the present invention.
FIG. 22 is an explanatory diagram of the process following FIG. 21 for forming an electron source on the back substrate of the second embodiment of the present invention.
FIG. 23 is an explanatory diagram of a process following FIG. 22 for forming an electron source on the back substrate of the second embodiment of the present invention.
FIG. 24 is an explanatory diagram of a process following FIG. 23 for forming an electron source on the back substrate of the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Back panel, 2 ... Front panel, 3 ... Sealing frame, 100 ... Electron source printed film, 101 ... Back substrate, 102 ... Fixing agent, 103 ... Carbon Nanotube, 105 ... nozzle, 106 ... dry ice, 701 ... cathode electrode, 702 ... gate electrode, 800 ... phosphor layer, 801 ... red (R) phosphor, 802 ..Green (G) phosphor, 803... Blue (B) phosphor, 804... Black matrix. 1301 ... Crater.

Claims (8)

A plurality of cathode electrodes, which are arranged in parallel in a second direction extending in the first direction and intersecting the first direction on the back substrate and having a large number of electron sources made of nanotubes, are insulated from the cathode electrode A plurality of gate electrodes extending in the second direction through the layer and arranged in parallel in the first direction to control extraction of electrons from the electron source, and an intersection of the cathode electrode and the gate electrode A back panel constituting a display area with a large number of pixels formed in
A self-luminous flat panel display comprising a plurality of color phosphor layers that emit light by excitation of electrons extracted from the electron source in the display area of the back panel and a front panel having an anode electrode,
The cathode electrode is formed by printing a paste in which nanotubes are mixed, and has a large number of micro craters on the printing surface, and the brushing rate of the nanotubes in the vicinity of the micro craters is a part away from the micro craters. Self-luminous flat display device characterized by being higher than that. The self-luminous flat display device according to claim 1, wherein the diameter and depth of the micro craters are randomly distributed. The self-luminous flat display device according to claim 1, wherein the nanotube is a carbon nanotube. A plurality of cathode electrodes, which are arranged in parallel in a second direction extending in the first direction and intersecting the first direction on the back substrate and having a large number of electron sources made of nanotubes, are insulated from the cathode electrode A plurality of gate electrodes extending in the second direction through the layer and arranged in parallel in the first direction to control extraction of electrons from the electron source, and an intersection of the cathode electrode and the gate electrode A back panel constituting a display area with a large number of pixels formed in
A method of manufacturing a self-luminous flat panel display comprising a front panel having a plurality of color phosphor layers that emit light by excitation of electrons extracted from the electron source in the display area of the back panel and an anode electrode,
Forming the cathode electrode by printing a paste in which nanotubes, conductive particles and a fixing agent are mixed; and
Baking and curing the printed paste; and
A self-luminous flat panel display comprising: a step of spraying solid fine particles of a substance that is solid at a low temperature and vaporizes at room temperature onto the cured printed surface to form a large number of micro craters and raise the nanotubes. Production method. 5. The method for manufacturing a self-luminous flat display device according to claim 4, wherein the solid fine particles are sprayed from a direction perpendicular to the printing surface or from an oblique direction. 6. The method of manufacturing a self-luminous flat panel display according to claim 5, wherein the solid fine particles are selectively sprayed only on the paste in the pixel portion. The method for manufacturing a self-luminous flat panel display according to any one of claims 4 to 6, wherein the solid fine particles are dry ice. 8. The method for manufacturing a self-luminous flat panel display device according to claim 4, wherein the nanotube is a carbon nanotube.

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