JPH04245136A - Manufacture of phosphor display panel - Google Patents

Abstract

PURPOSE:To prevent any electric short-circuit between phosphor layers by dipping an anode substrate into electrodeposition liquid which suspends phosphor powder so as to alternately electrify anode segment layers of mutually adjacent different electrodes in order to force phosphor powder to stick on the layers by electrophoresis. CONSTITUTION:An anode substrate where wiring layers 5A to 7E are provided on its insulated substrate and thereon an insulating layer and an anode segment layer are formed, is dipped into electrodeposition liquid suspending phosphor powder. Electrifying terminals are fixed to lead terminal parts 6AT-6ET, 7DT, 7ET so that electrodeposition solution may be positive and the segment layer of the anode electrode may be negative in order to electrify mutually adjacent segment layers, 5B, 6A, 6C, 7B alternately, for example to 6B. Thereby, phosphor powder can be stuck to segments by electrophoresis so as to prevent generation of any electric short-circuit by bridging due to phosphor powder between phosphor layers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fluorescent display panel that displays information by emitting light from a phosphor, and more particularly to a method for depositing a phosphor on an anode substrate.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 3, a method for manufacturing this type of fluorescent display panel involves applying an Al sputtering film to a glass substrate 1, forming a wiring layer 2 by photolithography, and then forming an anode segment layer. An insulating layer 3 is coated and formed on at least the wiring layer 2 except for the through-hole portions for establishing electrical conduction with the wiring layer 2. Furthermore, a dot layer 4 made of a conductive material is formed in the through hole portion.
Form by applying. Next, an anode segment layer 5 made of a conductive material is coated on the display pattern. The anode substrate thus created was coated with an electrodeposition solution (ZnO:Zn-based phosphor suspended in it).
Generally, the anode segment layer 5 is immersed in a mixture of pure water, ethanol, and acetone (aluminum nitrate and magnesium nitrate dissolved in a mixed solution of pure water, ethanol, and acetone) or sprayed with an electrodeposition solution on the anode substrate. By applying electricity to the wiring layer 2 and the electrodeposition liquid tank so that the tank containing the electrodeposition liquid serves as a positive electrode, the ZnO:Zn-based phosphor particles in the electrodeposition liquid are electrophoretically deposited on the anode segment layer 5.

A fluorescent display panel was manufactured by disposing a grid 7 and a filament 8 on the anode substrate on which a phosphor layer 6 had been obtained, sealing a cover glass 9, and evacuation.

0004

[Problems to be Solved by the Invention] In the above-mentioned method for manufacturing a fluorescent display panel, particularly in the method for forming a phosphor layer on an anode segment layer, it is impossible to connect the same electrode or different electrodes to the anode segment layer through the wiring layer. Since the current is applied all at once, a bridge is formed between the anode segment layers of adjacent different electrodes by the phosphor particles, resulting in an electrical short circuit.

This phenomenon is remarkable in graphic type fluorescent display panels in which the distance between different electrodes is narrow, and especially when the distance between different electrodes is 0.15 mm or less, the above-mentioned problem occurs at a high rate (approximately 3 to 3 mm). 15%), which caused problems in terms of manufacturing cost and quality.

[0006]

[Means for Solving the Problems] The method of manufacturing a fluorescent display panel according to the present invention, particularly the method of depositing a phosphor layer on an anode segment, involves dipping or electrodepositing an anode substrate in an electrodeposition solution in which phosphor powder is suspended. The method includes a step of electrophoretically depositing phosphor powder on each anode segment by applying electricity alternately to the anode segments of adjacent different electrodes through the wiring layer while spraying a liquid onto the anode substrate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a plan view showing an Al wiring layer portion of a 5×7 dot (dot diameter: 0.25 mm square, dot pitch: 0.4 mm) fluorescent display panel showing one embodiment of the present invention. In addition, in FIG. 1, 5A to 7E of the 5×7 dots are shown, and 1A to 4E are omitted and not shown. A
1 wiring layers 5A to 7E are formed on a glass substrate by photolithography using an Al sputtered film. Next, an insulating layer, a through-hole dot layer, and an anode segment layer in a display pattern are coated and formed using the same manufacturing method as the conventional fluorescent display panel shown in FIG. Note that 6 in Figure 1
AT-6ET, 7DT, and 7ET are lead terminals of corresponding segments 6A-6E, 7D, and 7E, respectively.

Next, an electrodeposition solution was prepared by suspending 20 g of ZnO:Zn-based phosphor in a mixed solution of 0.3 g of magnesium nitrate, 0.3 g of aluminum nitrate, 350 ml of pure water, 350 ml of ethyl alcohol, and 250 ml of acetone. . Put this electrodeposition solution into an electrodeposition tank equipped with metal electrodes,
The lead terminal portion 6AT of the anode substrate is placed so that the electrodeposition solution is positive and the anode segment layer of the anode substrate is negative.
Electrical terminals were attached to 6ET, 7DT, and 7ET, and the anode segment layer was immersed in an electrodeposition solution.

[0009] The current-carrying terminals are attached to the lead terminals by making it possible to alternately apply current to the segments 5B, 6A, 6C, and 7B for adjacent anode segment layers, for example, segment 6B shown in FIG. Electricity was applied as shown in 2.

FIG. 2(a) shows one example, and 15
0V voltage to segments 1A, 1C, 1E, 2B, 2
D, 3A, 3C, 3E, 4B, 4D, 5A, 5C, 5E
, 6B, 6D, 7A, 7C, 7E for 1.0 seconds,
No electricity for 0.5 seconds, then 1B, 1D, 2A, 2C,
2E, 3B, 3D, 4A, 4C, 4E, 5B, 5D, 6
150V for each segment of A, 6C, 6E, 7B, 7D
energize for 1.0 seconds. This operation was repeated for two cycles to obtain a dot-like phosphor layer with a phosphor layer thickness of 40 μm, a size of 0.25 mm square, and a pitch of 0.40 mm. A sealing frit layer was applied to the anode substrate thus obtained, a filament, a grid, and a lead were arranged, and the resultant was sealed with a cover glass and evacuated to produce a fluorescent display panel.

[0011] In this fluorescent display panel, a high-quality fluorescent display panel was obtained without any bridging between adjacent phosphor layers (a state in which adjacent segments are short-circuited by phosphor particles). .

FIG. 2(b) shows another example of the energization conditions for forming the phosphor layer. In this example, when energizing,
A high-quality fluorescent display panel was obtained without any bridging between the phosphor layers.

In the above embodiment, the case where the anode substrate is immersed in the electrodeposition solution has been described, but the same effect can be obtained even when electricity is applied while spraying the electrodeposition solution onto the segment portions of the anode substrate.

[0014]

As explained above, the present invention provides a method for manufacturing a fluorescent display panel which includes a step of electrophoretically depositing phosphor powder on an anode segment layer on an anode substrate.
The process of electrophoretically depositing the phosphor powder by alternately applying electricity through the wiring layers to the anode segment layers of adjacent different electrodes eliminates the gap between the phosphor layers, which conventionally occurs when the phosphor pattern spacing is narrow. Bridges made of phosphor powder can completely eliminate the incidence of electrical short-circuits.

[0015] Especially 0.25mm square, pitch 0.40mm
In the production of a graphic type fluorescent display panel with a high pattern density as described below, it is possible to provide a fluorescent display panel that has a remarkable improvement effect and is improved in terms of manufacturing cost and quality.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an Al wiring layer and a terminal portion of an anode substrate of the present invention.

FIG. 2 is a diagram showing voltage application conditions during electrodeposition of phosphor particles according to the present invention, with (a) and (b) showing different examples.

FIG. 3 is a cross-sectional view of a fluorescent display panel manufactured by a conventional manufacturing method.

[Explanation of symbols]

1 Glass substrate 2 Al wiring layer 3 Insulating layer 4 Through-hole dot layer 5 Anode segment layer 6 Phosphor layer 7 Grid 8 Filament 9 Cover glass 10 Frit layer for sealing 11 Lead 12 Lead terminal 1A to 7E Segment

Claims (1)

[Claims] 1. An anode substrate having at least a wiring layer, an insulating layer, and an anode segment layer formed on an insulating substrate is immersed in an electrolytic solution in which phosphor powder is suspended, or is passed through the wiring layer while being sprayed with the electrolytic solution. In a method for manufacturing a fluorescent display panel, which includes a step of electrophoretically depositing phosphor powder on an anode segment layer by energizing the anode segment layer, the anode segment layers of adjacent different electrodes are alternately energized through a wiring layer. 1. A method for manufacturing a fluorescent display panel, comprising the step of electrophoretically depositing a phosphor powder.