JPH1167087A - Phosphor screen and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce residues and color mixing and to prevent the drop of phosphors by providing a fine particle layer having a smaller average particle diameter than the phosphors of phosphor layers, between an electrode layer on a glass substrate and each of the phosphor layers deposited over the electrode layer. SOLUTION: A fine particle layer 2 made preferably from a phosphor and having an average particle diameter of 1 μm or less is formed between the anode of a transparent electrode 3 having an electrode pattern made of ITO or the like on a glass substrate 4 and each of green, blue, and red phosphor layers 1. Thus, since a force working on an interface as the result of van der Waals forces becomes great, the bonding strength of the phosphor is enhanced although polyvinyl alcohol or the like is not used. Inside an electrodeposition liquid in which mixed phosphor powders with average particle diameters of, e.g. 3 μm and 0.3 μm, are dispersed, the green, blue, and red phosphors are sequentially electrodeposited on the glass substrate 4 having the transparent electrode 3. Since phosphors of the smaller particle diameters are first electrodeposited because of electrostatic attracting force, gravitational force, buoyancy, and the like, the phosphor layers 1 and the fine particle layer 2 are deposited in a single process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a phosphor screen of various displays and a method of manufacturing the same, and more particularly, to a phosphor screen of a field emission display which is a flat panel display type display device and a method of manufacturing the same.

[0002]

2. Description of the Related Art A field emission display (field emission display, FED) which combines a cathode substrate provided with a field emission type element array (field emitter array, FEA) and an anode substrate provided with a phosphor pattern has a high luminance. Due to the features of high definition and low power consumption, expectations for flat panel displays are increasing. For this type of display,
Monochrome and full-color displays have already been prototyped (for example, described in IEDM91-p.197).

[0003] The FED (field emission display) includes an FEA (field emitter array),
A cathode substrate on which an emitter wiring and a gate wiring are formed, and an anode substrate on which an anode electrode and a phosphor pattern are formed are arranged to face each other at a predetermined interval. In the FED, electrons are emitted and controlled from the FEA, and the phosphor on the anode substrate is excited to emit light.

On the anode substrate, for example, a striped anode electrode made of ITO is formed, and red (R), green (G), and blue (B) are respectively provided at predetermined positions on the anode electrode. Phosphors are deposited in order.

An electrodeposition method is known as one of the methods for attaching the phosphor onto the electrode pattern.

That is, in the electrodeposition method, in a solution containing polyvalent ions (Al ^{3 +} , La ^{3 +,} etc.) for charging the surface of the phosphor particles, a fluorescent electrode is applied by applying a DC voltage to a desired pattern of electrodes as a cathode. This is a method in which body particles are caused to migrate and a phosphor is attached on the electrode pattern. Further, when it is desired to form a phosphor pattern composed of phosphors of a plurality of kinds of fluorescent colors, it is known and disclosed, for example, in Japanese Patent Publication No. 57-55172 that the above steps are repeated for each color.

This electrodeposition method can form a phosphor layer with excellent uniformity, can form a phosphor layer only on an electrode pattern, has a high film forming speed, voltage, and electrodeposition time. , The thickness of the phosphor layer can be easily controlled.

However, in the above-described method for forming the phosphor layer,
The phosphor layer has weak adhesion to the glass substrate, causing the phosphor to fall off. Therefore, as a means for solving this problem, a method of electrodepositing polyvinyl alcohol simultaneously with the phosphor,
This is proposed in Japanese Patent Application Laid-Open No. 50-73560.

[0009]

In the above-described method, however, the adhesion of the phosphor is improved by using polyvinyl alcohol. However, the phosphor adheres to unnecessary portions, and residue and color mixing are prevented. There is a problem that it causes deterioration of color purity and luminance as well as causes.

The present invention has been made in order to solve the above-mentioned problems, and provides a phosphor screen having a structure with little residue or color mixture and capable of preventing the phosphor from falling off, and a method of manufacturing the same. The purpose is to:

[0011]

In order to achieve the above object, the present invention provides an electrode layer formed on a glass substrate and a phosphor laminated on the electrode layer. And a fine particle layer having a smaller average particle size than the phosphor of the phosphor layer is formed between each electrode layer and the phosphor layer.

According to a second aspect of the present invention, in the fluorescent screen according to the first aspect, the fine particle layer is made of a phosphor.

According to a third aspect of the present invention, in the phosphor screen according to the first or second aspect, the phosphor of the fine particle layer has an average particle diameter of 1 μm or less.

According to a fourth aspect of the present invention, there is provided an electrode layer formed on a glass substrate, and a phosphor layer laminated on the electrode layer, wherein between the electrode layer and the phosphor layer, What is claimed is: 1. A method for producing a phosphor screen, comprising forming a fine particle layer of a phosphor having an average particle diameter of 1 μm or less, wherein the phosphor layer and the fine particle layer are laminated in a single process by an electrodeposition method. A method for manufacturing a phosphor screen characterized by the following.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a cross section showing an example of the phosphor screen of the present invention. FIG. 2 is a schematic explanatory view showing the electrodeposition of the fine particle layer and the phosphor layer in the method for producing a phosphor screen of the present invention. As shown in FIGS. 1 and 2, the phosphor screen of the present invention is obtained by forming a fine particle layer having a smaller average particle size than the phosphor of the phosphor layer between each electrode layer and the phosphor layer. The layer is made of a phosphor, and the phosphor has an average particle size of 1 μm or less. Further, the present invention is a method for producing a phosphor screen in which the phosphor layer and the fine particle layer are laminated by a single process and by an electrodeposition method.

According to the present invention, the phosphor can be prevented from falling off by forming the fine particle layer between each electrode and the phosphor layer. In order to prevent the phosphor from falling off, it is desirable that the adhesion between the phosphor particles and between the phosphor particles and the electrode pattern be large. That is, the main force acting on the interface is the van der Waals force, which becomes stronger as the contact area increases. Therefore, the smaller the particle size, the larger the number of contact points and the larger the total contact area, so that the force acting on the interface increases. Therefore, the adhesive force between the electrode pattern and the fine particle layer increases.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment will be described with reference to the drawings.

<Embodiment 1> FIG. 1 shows an embodiment of the present invention. In this embodiment, red Y ₂ O ₃ : Eu, green ZnO: Zn, blue Y ₂ SiO
₅ : Ce was used, but the present invention is not limited to this, and other known phosphors may be used.

Although the obtuse edge type is used as the FEA, other shapes such as a cone type may be used.

A method for manufacturing the phosphor screen shown in FIG. 1 will be described.

First, a glass substrate 4 on which an ITO film is formed is prepared, and an anode electrode pattern 3 is formed by photolithography and wet etching. The anode electrode was commonly connected to an anode extraction electrode for each color.

Next, the glass substrate 4 is placed in an electrodeposition liquid 6 in which a phosphor of a required color is dispersed, and green, blue and red phosphors are sequentially electrodeposited.

As the phosphor, powder obtained by mixing a phosphor having an average particle diameter of 3 μm and a phosphor having an average particle diameter of 0.3 μm was used. As the electrodeposition liquid 6 for dispersing the phosphor, as a solvent,
A liquid sufficiently mixed with isopropyl alcohol, acetone, etc., and aluminum nitrate, gallium nitrate, magnesium nitrate, etc. as an electrolyte was used.

FIG. 2 is a schematic explanatory view showing the adhesion of the fine particle layer and the phosphor layer by the electrodeposition method using the electrodeposition apparatus used in the present embodiment. In the electrodeposition apparatus shown in FIG. Is provided with a substrate (fluorescent screen) 7 on which a phosphor is laminated, and an electrode substrate 8 for applying an electric field is provided below.

Electrodeposition of the phosphor is performed by connecting the negative electrode to the electrode on which the phosphor is laminated and the positive electrode to the voltage applying electrode.

At the time of the electrodeposition, the phosphor is subjected to an upward force by electrostatic attraction, a downward force by (gravity-buoyancy), and a viscous resistance force. While the electrostatic attraction does not depend much on the particle size, (gravitational force-buoyancy) increases as the particle size increases (in the case of phosphor density> solvent density). Therefore, in the arrangement shown in FIG. 2, the smaller the particle size, the higher the electrodeposition speed,
A phosphor layer having an average particle diameter of 0.3 μm is first electrodeposited to form a fine particle layer 2, and a phosphor layer having an average particle diameter of 3 μm is also added later to form a phosphor layer 1 containing both. become.

The fine particle layer 2 is made of a phosphor having an average particle diameter of 0.3 μm, and has a large adhesive force with the electrode pattern. Also,
The phosphor layer 1 on the fine particle layer 2 is composed of a powder in which a phosphor having an average particle diameter of 3 μm and a phosphor having an average particle diameter of 0.3 μm are mixed, and the adhesive force between the fine particle layer and the phosphor layer is also increased.

No residue or color mixture was observed on the surface of the phosphor layer 1 by the electrodeposition method. Moreover, a panel was formed and a luminescence test was performed, but no dropout of the phosphor was observed.

<Example 2> As a phosphor dispersed in the electrodeposition solution 6 of the schematic electrodeposition apparatus shown in FIG. 2, powder obtained by mixing a phosphor having an average particle diameter of 3 μm and a phosphor having an average particle diameter of 1 μm or less was used. A phosphor layer was prepared in the same manner as in Example 1 except that the phosphor layer was used.

No residue or color mixture was observed on one surface of the prepared phosphor layer. I made a panel and performed a luminescence test,
No dropout of the phosphor was observed.

[0031]

According to the present invention, since the fine particle layer is formed between each electrode and the phosphor, the smaller the particle size, the more the contact points and the larger the total contact area. Becomes larger. Therefore, the adhesive force between the electrode pattern and the fine particle layer was increased, and it was possible to prevent the phosphor from falling off. Also, on the phosphor layer surface by this electrodeposition method,
No residue or color mixture was found. Further paneling was performed and a luminescence test was performed, but no dropout of the phosphor was observed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a cross section showing an example of a phosphor screen of the present invention.

FIG. 2 shows a fine particle layer in the method for producing a phosphor screen of the present invention;
It is a schematic explanatory drawing which shows the electrodeposition of a fluorescent substance layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Phosphor layer 2 ... Particle layer 3 ... Transparent electrode 4 ... Glass substrate 5 ... Electrodeposition bath 6 ... Electrodeposition liquid 7 ... Fluorescent surface 8 ... Electric field application substrate 9 ... Stirring device

Claims (4)

[Claims] 1. A phosphor screen comprising an electrode layer formed on a glass substrate and a phosphor layer laminated on the electrode layer, wherein a phosphor layer is provided between the electrode layer and the phosphor layer. A phosphor screen, wherein a fine particle layer having a smaller average particle size than the phosphor of the phosphor layer is formed. 2. The phosphor screen according to claim 1, wherein said fine particle layer is made of a phosphor. 3. The phosphor of the fine particle layer has an average particle diameter of 1 μm.
The phosphor screen according to claim 1 or 2, wherein m is equal to or less than m. 4. An electrode layer formed on a glass substrate, and a phosphor layer laminated on the electrode layer, wherein an average particle size between the electrode layer and the phosphor layer is 1 μm. A method for producing a phosphor screen by forming a fine particle layer of the following phosphor, wherein the phosphor layer and the fine particle layer are laminated in a single process and by an electrodeposition method. Surface manufacturing method.