JP2005085465A - Fluorescent display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a minute phosphor layer of a fluorescent display tube with high precision by an ink jet method. <P>SOLUTION: An anode electrode 104 has a porous structure comprising a plurality of hydrophilic carbonization particles, on which a phosphor layer 105 is formed by forming a pattern 105a by an ink jet method using phosphor ink wherein phosphor particles are dispersed to inhibit the phosphor ink ejected by the ink jet method from spreading on the anode electrode 104. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fluorescent display device, and more particularly, to a dot matrix type fluorescent display device in which a large number of display pixels having a phosphor layer are arranged in a matrix and a method for manufacturing the same.

  The fluorescent display device is an electron tube that uses a pattern of the emitted phosphor for display by causing electrons emitted from an electron emission source to collide with the phosphor to emit light in a vacuum container. In a general fluorescent display device, an anode in which a phosphor layer is formed in a vacuum envelope, a filament cathode stretched over the anode, and a grid electrode provided therebetween The thermoelectrons emitted from the filament cathode are controlled by the grid electrode so as to collide with the surface of the phosphor layer (see Patent Documents 1 and 2).

  In one type of such a fluorescent display device, as shown in FIG. 5, a plurality of light emitting pixels 506 having a phosphor layer 505 are arranged in a matrix on a square anode electrode 504, and each light emitting pixel 506 is arranged. There is a dot matrix type fluorescent display device as a pixel for display. FIG. 5 is a schematic cross-sectional view showing a part of an envelope (not shown) of such a fluorescent display device. In this fluorescent display device, the light emitting pixel 506 is formed on the wiring layer 502 formed on the substrate 501 constituting a part of the envelope with the interlayer insulating layer 503 interposed therebetween. A plurality of grid electrodes 507 are disposed above the light emitting pixels 506, and a filament cathode 508 is stretched over them.

  A face glass 509 made of a transparent member such as glass is disposed above the filament cathode 508. The face glass 509 is disposed on a frame-like side wall member (not shown) provided at the peripheral edge of the substrate 501, and the substrate 501, the side wall member, and the face glass 509 are firmly fixed without any gaps, and the vacuum envelope is thereby formed. It is configured.

  Incidentally, the phosphor layer 505 of the dot matrix type phosphor display device configured as described above is generally formed by a pattern forming technique such as a screen printing method. However, as display density increases, the size and arrangement of dots become higher definition, and conventional screen printing methods may not meet the requirements in terms of accuracy.

On the other hand, pattern formation by photolithography technology used in the manufacture of semiconductor devices such as LSI makes it possible to form patterns with higher accuracy. However, when this technique is used, more manufacturing apparatuses are required and the number of manufacturing processes is increased, leading to an increase in manufacturing cost.
As a technique for solving these problems, there is a pattern forming technique by an ink jet method (see Patent Documents 3, 4, 5, and 6). According to this technique, it is possible to obtain high accuracy in pattern dimensions and formation positions without increasing the number of processes and cost.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP-A-9-147767 JP 2000-294177 A Japanese Patent Laid-Open No. 11-204529 Japanese Patent Laid-Open No. 11-340129 JP 2002-347238 A JP 2003-159796 A

  By the way, in the pattern formation by the ink jet method, it is possible to form a finer pattern by reducing the diameter of the nozzle protruding the material ink. However, the material forming the phosphor layer cannot make the diameter of the nozzle so small because the phosphor particles cannot be made too small. For this reason, when it is going to form the fluorescent substance layer of a fluorescent display apparatus with an inkjet method, it is not easy to form a highly accurate fine pattern.

  In the pattern formation by the ink jet method, the material of the pattern to be formed is ejected from the nozzle as an ink having a low viscosity. In many cases, the amount of ink necessary for forming a pattern having a desired dimension is ejected at a time in a short time. As a result, it is difficult to suppress the spread of the ejected ink, the pattern is formed wider than the design value, and the pattern edge is wavy, increasing the pattern dimensional accuracy. Is not easy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to enable a fine phosphor layer of a fluorescent display device to be formed with high accuracy by an inkjet method.

A fluorescent display device according to the present invention is formed on a vacuum envelope including a face portion made of a transparent material and a substrate disposed so as to face the face portion, and an inner surface of the vacuum envelope of the substrate. A wiring layer; a plurality of anode electrodes formed on an insulating layer formed on the wiring layer and connected to the wiring layer; a phosphor layer formed on each of the anode electrodes; and a vacuum envelope A plurality of light-emitting pixels each consisting of an anode electrode and a phosphor layer are provided above a display area arranged in a matrix, and a grid envelope is provided above the grid electrode inside the vacuum envelope. The anode electrode has a porous structure composed of a plurality of hydrophilic carbon particles, and the phosphor layer uses phosphor ink in which phosphor particles are dispersed. By inkjet method And it is formed.
In this apparatus, the anode electrode on which the phosphor layer is formed is in a state where liquid is easily impregnated.

  In the fluorescent display device, the anode electrode may have a recess formed on the upper surface, and the phosphor layer may be formed inside the recess on the upper surface of the anode electrode.

The fluorescent display device manufacturing method according to the present invention includes a vacuum envelope including a face portion made of a transparent material and a substrate disposed so as to face the face portion, and an inner surface of the vacuum envelope of the substrate. A formed wiring layer; a plurality of anode electrodes formed on an insulating layer formed on the wiring layer and connected to the wiring layer; a phosphor layer formed on each of the anode electrodes; and a vacuum A plurality of grid electrodes constructed above a display area in which a plurality of light emitting pixels composed of an anode electrode and a phosphor layer are arranged in a matrix inside the envelope, and above the grid electrodes inside the vacuum envelope In the method for manufacturing a fluorescent display device comprising an electron emission portion provided on the anode, the anode electrode is formed from a plurality of hydrophilic carbon particles to have a porous structure, and the phosphor layer is composed of phosphor particles. Dispersed fireflies It is obtained so as to form by the ink jet method using the body ink.
According to this manufacturing method, the anode electrode on which the phosphor layer is formed is formed in a state where the liquid is easily impregnated.

  In the above manufacturing method, the anode electrode may be formed by an ink jet method using a carbon ink in which a plurality of carbon particles having hydrophilicity are dispersed. Further, the anode electrode may be formed with a recess on the upper surface, and the phosphor layer may be formed inside the recess on the upper surface of the anode electrode. Moreover, what is necessary is just to form a recessed part by forming a bank in the peripheral edge part of the upper surface of an anode electrode.

  In the present invention, the anode electrode has a porous structure composed of a plurality of carbon particles having hydrophilicity, and a pattern is formed thereon by an inkjet method using a phosphor ink in which phosphor particles are dispersed. Thus, a phosphor layer was formed. As a result, according to the present invention, the phosphor ink discharged by the ink jet method is suppressed from spreading on the anode electrode, and the phosphor ink is suppressed from flowing out from the anode electrode. In addition to this, a concave portion is formed on the upper surface of the anode electrode by providing a frame-like bank and the phosphor ink is discharged into the recess, so that the phosphor ink can be prevented from flowing out more efficiently. become. As a result, according to the present invention, it is possible to obtain an excellent effect that the fine phosphor layer of the fluorescent display device can be formed with high accuracy by the ink jet method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a process diagram showing a partial process example of a method for manufacturing a fluorescent display device according to a first embodiment of the present invention. First, as shown in FIG. 1A, an insulating substrate 101 made of glass or the like is prepared, and a wiring layer 102 is formed thereon. The wiring layer 102 can be formed, for example, by printing paste-like ink containing the material of the wiring layer 102 by a screen printing method, forming a desired pattern made of the ink, and firing these.

Next, as shown in FIG. 1B, an insulating material film is formed so as to cover the wiring layer 102 to form an interlayer insulating layer 103, and any of the wiring layers 102 is formed at a predetermined position of the interlayer insulating layer 103. A through hole communicating with the wiring is formed.
Next, as shown in FIG. 1C, an anode electrode 104 connected to a predetermined wiring through a through hole of the interlayer insulating layer 103 is formed in a predetermined display area of the insulating substrate 101. The anode electrode 104 is a pattern composed of a plurality of carbon particles having a particle size of several nm, and is formed by an ink jet method.

  A method for forming the anode electrode 104 will be described. First, a carbon ink made of hydrophilic carbon particles (manufactured by Tokai Carbon) is prepared. The carbon ink is obtained by dispersing the carbon ink in a binder composed of a resin or the like. When the carbon ink is prepared, a predetermined pattern made of the carbon ink is printed on the interlayer insulating layer 103 by a well-known ink jet method. Since carbon particles have a fine particle size of several nanometers, a nozzle having a small hole diameter of about 20 μm can be used as a head hole of the ink jet nozzle in printing by the ink jet method.

  After forming a predetermined pattern made of carbon ink as described above, the anode electrode 104 made of a plurality of carbon particles is formed by firing, for example, by heating to 500 ° C. The anode electrode 104 formed in this way is formed in a porous shape having a plurality of pores between each partially bonded carbon particle. Note that the anode electrode 104 is a square or a rectangle whose dimension in the plane direction of the insulating substrate 101 is about 0.3 mm.

  Next, a phosphor ink to be a phosphor layer having a desired emission color is prepared. The phosphor ink is obtained by dispersing a plurality of phosphor particles in a binder made of a resin or the like. The binder is, for example, from melamine resin (Sumitomo Chemical: Sumimar M-5-W), acrylic resin (Mitsubishi Rayon: Dianar HW-135), dispersant (Kao: Emulgen 420), glycerin, ion-exchanged water. (See JP 2003-096340 A). Moreover, in order to enable pattern formation by the inkjet method, the phosphor ink has a low viscosity of 3 to 10 cp.

  When such a phosphor ink is prepared, a predetermined pattern 105a made of the phosphor ink is printed on each anode electrode 104 as shown in FIG. 1D by a well-known ink jet method. The phosphor particles have a particle size of about 0.5 to 6 μm, and in the printing by the ink jet method, a nozzle having a hole diameter of about 70 μm can be used as a head hole of the ink jet nozzle.

  As described above, since the anode electrode 104 is formed in a porous shape, and the carbon particles constituting the anode electrode 104 are hydrophilic, a solvent such as a phosphor ink solvent or water discharged from an inkjet nozzle is used as the anode electrode. 104 is absorbed. By forming the pattern 105a in this state, it is possible to suppress the pattern 105a from spreading out from the anode electrode 104.

  As described above, since the particle size of the phosphor particles is about 0.5 to 6 μm, the nozzle system of the inkjet nozzle is about 70 μm. Further, the viscosity of the phosphor ink is low. For this reason, it is not easy to form the pattern 105a in the same size as the small anode electrode 104 of about 0.3 mm square.

  However, according to the present embodiment, the lower-layer anode electrode 104 is impregnated with the solvent, and the viscosity of the phosphor ink supplied on the anode electrode 104 is sequentially increased. As a result, the spread of the supplied phosphor ink is suppressed on the anode electrode 104, and the phosphor ink pattern 105a can be formed without flowing out from the anode electrode 104. Become.

As described above, after the pattern 105a is formed in a state in which the undesired spread is suppressed, these are fired at a temperature of about 500 ° C., and as shown in FIG. It is assumed that the phosphor layer 105 is formed.
After the phosphor layer 105 is formed in this way, the grid electrode is arranged so as to cover the upper part of the display area, and the filament electrode is stretched by the anchor and support arranged outside the display area. To do.

  Next, terminals are arranged around the insulating substrate 101 and each terminal is connected to a predetermined portion of the wiring layer 102. Thereafter, a frame (side wall member) is disposed on the peripheral edge of the insulating substrate 101, and face glass is disposed on the frame and closely fixed without any gap therebetween. Form an envelope. After forming the vacuum envelope in this way, the inside of the vacuum envelope is reduced to a predetermined pressure, whereby the fluorescent display device is completed. The face glass (face part) is not limited to glass, and may be a plate member made of a transparent material having heat resistance.

  The completed fluorescent display device is configured, for example, as shown in FIGS. 2 (a) and 2 (b). 2 (a) and 2 (b) are schematic cross-sectional views showing a partial configuration of the fluorescent display device according to the present embodiment, and FIG. 2 (b) is a partially enlarged view of FIG. 2 (a). FIG. Briefly describing this fluorescent display device, a wiring layer 102 is formed on an insulating substrate 101, and an interlayer insulating layer 103 is formed on the wiring layer 102.

In the display region on the interlayer insulating layer 103, a plurality of anode electrodes 104 connected to a predetermined portion of the wiring layer 102 through through holes are formed. The anode electrodes 104 are arranged in a matrix, for example, and a phosphor layer 105 is provided on each anode electrode 104.
A plurality of grid electrodes 107 are arranged on a plurality of light emitting pixels 106 composed of the anode electrode 104 and the phosphor layer 105, and a filament cathode 108 is stretched thereon.

A face glass 109 made of a transparent member such as glass is disposed above the filament cathode 108. The face glass 109 is disposed in a frame (not shown) provided at the peripheral edge of the insulating substrate 101. The phosphor layer 105 is formed in a smaller area than the anode electrode 104.
In the present embodiment described above, the anode electrode is made of a porous body made of an aggregate of hydrophilic carbon particles. Thus, according to the present embodiment, the phosphor ink pattern formed by the ink jet method can be prevented from spreading more than necessary on the anode electrode.

[Embodiment 2]
Next, a second embodiment of the present invention will be described.
FIG. 3 is a process diagram showing a partial process example of the method for manufacturing the fluorescent display device according to the first embodiment of the present invention. First, as shown in FIG. 3A, an insulating substrate 101 made of glass or the like is prepared, and a wiring layer 102 is formed thereon. The wiring layer 102 can be formed, for example, by printing paste-like ink containing the material of the wiring layer 102 by a screen printing method, forming a desired pattern made of the ink, and firing these.

Next, as illustrated in FIG. 3B, an insulating material film is formed so as to cover the wiring layer 102 to form an interlayer insulating layer 103, and any of the wiring layers 102 is formed at predetermined positions of the interlayer insulating layer 103. A through hole communicating with the wiring is formed.
Next, as shown in FIG. 3C, a lower pattern 304 a having a dimension of about 0.3 mm square serving as an anode electrode connected to a predetermined wiring through the through hole of the interlayer insulating layer 103 is formed on the insulating substrate 101. It is formed in a predetermined display area. The lower pattern 304a is a pattern made of a plurality of carbon particles having a particle size of several nanometers, and is formed by an inkjet method.

  A method for forming the lower pattern 304a will be described. First, a carbon ink made of hydrophilic carbon particles (manufactured by Tokai Carbon) is prepared. The carbon ink is obtained by dispersing the carbon ink in a binder composed of a resin or the like. When the carbon ink is prepared, a predetermined pattern (lower pattern 304a) made of the carbon ink is printed on the interlayer insulating layer 103 by a well-known ink jet method. Since carbon particles have a fine particle size of several nanometers, a nozzle having a small hole diameter of about 20 μm can be used as a head hole of the ink jet nozzle in printing by the ink jet method.

  After forming the lower pattern 304a as described above, a frame pattern 304b is formed on the lower pattern 304a by the same ink jet method as shown in FIG. The frame pattern 304b is a frame-like pattern having a width of 20 μm and a height of about 10 μm, which is disposed at the upper peripheral edge of the lower pattern 304a.

As described above, after the lower pattern 304a and the frame pattern 304b are formed by the ink jet method, they are baked by heating to, for example, 500 ° C., and are formed of a plurality of carbon particles, and provided with a recess by a bank at the peripheral edge. The anode electrode 304 is formed (FIG. 3E). The anode electrode 304 formed in this way is formed in a porous shape having a plurality of pores between each partially bonded carbon particle.
Thereafter, in the same manner as described above, as shown in FIG. 3F, the phosphor layer 105 is formed in the recess of the anode electrode 304 by the ink jet method.

According to the present embodiment, the lower-layer anode electrode 304 is impregnated with the solvent, and the viscosity of the phosphor ink supplied on the anode electrode 304 is successively increased. As a result, the spread of the supplied phosphor ink is suppressed on the anode electrode 304.
In addition, according to the present embodiment, a bank is provided at the peripheral end portion of the anode electrode 304, and the phosphor layer 105 is formed in the concave portion inside the bank, so that the fluorescence supplied from the inkjet nozzle can be formed. The spread of the body ink is prevented by the bank.

After the phosphor layer 105 is formed in this way, the grid electrode is arranged so as to cover the upper part of the display area, and the filament electrode is stretched by the anchor and support arranged outside the display area. To do.
Next, terminals are arranged around the insulating substrate 101 and each terminal is connected to a predetermined portion of the wiring layer 102. Thereafter, a frame (side wall member) is disposed on the peripheral edge of the insulating substrate 101, and face glass is disposed on the frame and closely fixed without any gap therebetween. Form an envelope. After forming the vacuum envelope in this way, the inside of the vacuum envelope is reduced to a predetermined pressure, whereby the fluorescent display device is completed.

  The completed fluorescent display device is configured, for example, as shown in FIGS. 4 (a) and 4 (b). 4 (a) and 4 (b) are schematic cross-sectional views showing a partial configuration of the fluorescent display device according to the present embodiment, and FIG. 4 (b) is a partially enlarged view of FIG. 4 (a). FIG. Briefly describing this fluorescent display device, a wiring layer 102 is formed on an insulating substrate 101, and an interlayer insulating layer 103 is formed on the wiring layer 102.

In the display region on the interlayer insulating layer 103, a plurality of anode electrodes 304 connected to a predetermined portion of the wiring layer 102 through through holes are formed. The anode electrode 304 is arranged in a matrix, for example, and the phosphor layer 105 is provided in a recess on each anode electrode 304.
A plurality of grid electrodes 107 are disposed on the plurality of light emitting pixels 106 composed of the anode electrode 304 and the phosphor layer 105, and a filament cathode 108 is stretched thereon.

A face glass 109 made of a transparent member such as glass is disposed above the filament cathode 108. The face glass 109 is disposed in a frame (not shown) provided at the peripheral edge of the insulating substrate 101. The phosphor layer 105 is formed in a smaller area than the anode electrode 304.
In the present embodiment described above, the bank is provided on the anode electrode 304, and the phosphor ink is supplied into the concave portion formed by the bank to form this pattern. Therefore, the spread of the phosphor ink is suppressed by the bank. Become so.

It is process drawing for demonstrating the manufacturing method of the fluorescence display apparatus in embodiment of this invention. It is a schematic sectional drawing which shows the structural example of the fluorescence display apparatus in embodiment of this invention. It is process drawing for demonstrating the other example of a manufacturing method of the fluorescence display apparatus in embodiment of this invention. It is a schematic sectional drawing which shows the other structural example of the fluorescence display apparatus in embodiment of this invention. It is sectional drawing which shows the structure of the conventional fluorescence display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Insulating substrate, 102 ... Wiring layer, 103 ... Interlayer insulating layer, 104 ... Anode electrode, 105 ... Phosphor layer, 105a ... Pattern, 106 ... Light emitting pixel, 107 ... Grid electrode, 108 ... Filament cathode, 109 ... Face glass .

Claims (6)

A vacuum envelope comprising a face portion made of a transparent material and a substrate disposed opposite to the face portion;
A wiring layer formed on the inner surface of the vacuum envelope of the substrate;
A plurality of anode electrodes formed on an insulating layer formed on the wiring layer and connected to the wiring layer;
A phosphor layer formed on each of the anode electrodes;
A plurality of grid electrodes laid above a display region in which a plurality of light emitting pixels composed of the anode electrode and the phosphor layer are arranged in a matrix in the vacuum envelope;
An electron emission portion provided above the grid electrode inside the vacuum envelope, and
The anode electrode has a porous structure composed of a plurality of carbon particles having hydrophilicity,
The phosphor display device, wherein the phosphor layer is formed by an ink jet method using a phosphor ink in which phosphor particles are dispersed. The fluorescent display device according to claim 1,
The anode electrode has a recess formed on the upper surface,
The phosphor display device, wherein the phosphor layer is formed inside a recess on an upper surface of the anode electrode. A vacuum envelope comprising a face portion made of a transparent material and a substrate disposed opposite to the face portion, a wiring layer formed on the inner surface of the vacuum envelope of the substrate, and the wiring layer A plurality of anode electrodes formed on an insulating layer formed on the substrate and connected to the wiring layer; a phosphor layer formed on each of the anode electrodes; and the anode within the vacuum envelope A plurality of grid electrodes constructed above a display region in which a plurality of light-emitting pixels each composed of an electrode and a phosphor layer are arranged in a matrix, and electrons provided above the grid electrodes in the vacuum envelope In the manufacturing method of the fluorescent display device composed of the emission part,
The anode electrode is formed from a plurality of hydrophilic carbon particles to have a porous structure,
The phosphor layer is formed by an inkjet method using a phosphor ink in which phosphor particles are dispersed. A method for manufacturing a phosphor display device, comprising: In the manufacturing method of the fluorescent display device according to claim 3,
A method for manufacturing a fluorescent display device, wherein the anode electrode is formed by an ink jet method using a carbon ink in which a plurality of carbon particles having hydrophilicity are dispersed. In the manufacturing method of the fluorescent display device according to claim 3 or 4,
The anode electrode is formed with a recess on the upper surface,
The phosphor layer is formed inside a recess on the upper surface of the anode electrode. A method for manufacturing a fluorescent display device, wherein: 6. The method of manufacturing a fluorescent display device according to claim 5, wherein the concave portion is formed by forming a bank on a peripheral end portion of the upper surface of the anode electrode.

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