JPS62276736A - Fluorescent character display tube - Google Patents

Abstract

PURPOSE:To improve adhesive property at an interface between a phosphor layer and a positive electrode by forming a layer consisting of striped, mesh or dotted SiO2 on the positive electrode and applying phosphor to make a phosphor layer on the positive electrode provided with the SiO2 layer. CONSTITUTION:An insulating substrate 1 is coated with an Al thin film to form a feeding wire 10 and a positive electrode 11. And an insulating paste consisting of glass powder of a low melting point, pigment and on organic binder is applied to the substrate and baked to provide an insulating layer 3. Then, a SiO2 paste consisting of silicon dioxide and an organic binder is printed in stripes on the positive electrode 11 and baked to form a striped SiO2 layer 21. Following this, phosphor paste consisting of ZnO:Zn phosphor and an organic binder is applied to a part of the positive electrode 11 forming SiO2 layer and dried to form phosphor layer(1)61, and further phosphor paste consisting of (Zn, Cd) SiAg, C1 series phosphor and an organic binder is applied to the remaining part of the positive electrode 11 to form SiO2 and baked to form a phosphor (2)62.

Description

[Detailed Description of the Invention] 1. Detailed Description of the Invention [Industrial Application Field] The present invention displays numbers, symbols, designs, etc. by light emission from a phosphor layer coated on an anode electrode made of a thin Al film. This relates to the structure of a fluorescent display tube.

[Conventional technology]

The anode coated with a phosphor layer is bombarded with electrons emitted from a filament to excite and emit light, and the display is observed from the phosphor coated surface. Due to the high density of the power supply wiring, there is a type of fluorescent display tube in which the anode electrode and the power supply wiring are formed of a thin Al film.

This type of fluorescent display tube has, for example, the structure shown in FIGS. 2 and 3. That is, an Al thin film is formed by sputtering on an insulating substrate 1 such as glass, and this is then photo-etched. Then, a power supply wiring lO and an anode electrode 911 are formed. This anode electrode group 11) has an insulating layer 3t-
After coating and forming, a phosphor having a desired emission color is sequentially applied to a desired position on the anode electrode 11 in a desired pattern, and heat treatment is performed at about 500°C to form a display pattern 12 consisting of phosphor layers 61 and 62. Form. A mesh-like grid, filament 8 and external lead 13 are arranged on the anode substrate thus obtained, covered with a cover glass 12 and sealed, and further the inside is evacuated to a high vacuum state and sealed.

[Problem that the invention seeks to solve]

The above-mentioned conventional fluorescent display tube of this type has phosphor layers 61, 6 formed by coating on the anode electrode ll made of a thin Al film.
There was a problem that the adhesive strength of No. 2 was low and it was easy to peel off.

That is, while the anode electrode, which is the base of the phosphor layer, is formed by sputtering Al and has an extremely smooth surface, the phosphor layer is formed of an aggregate of nearly spherical phosphor particles, so the Al
At the interface between the thin film and the phosphor layer, the contact area between the two is small;
The phosphor layer did not have sufficient adhesive strength to withstand external impacts, and the phosphor layer peeled off during the process after the phosphor layer was formed.

%, the average particle size of the phosphor is relatively large from 8 μ arc to 12 μ arc (Zn, Cd)S; AII, C4 and (Zn).

Cd) S; Au, AJ arrangement [ZnS; Au, A7!
(7) For each phosphor, the phenomenon of peeling of the phosphor layer is remarkable.
There were some cases where peeling occurred due to the impact force of light tapping (approximately 200 G in terms of gravitational acceleration). The impact resistance that is generally said to be necessary for the quality of anode substrates is 1.0 when converted to gravitational acceleration.
It's OOG.

[A great way to solve problems]

The fluorescent display tube of the present invention is a type of fluorescent display tube in which a display consisting of light emission from a phosphor coated and formed on an anode electrode made of a thin Al film is observed from a surface coated with the phosphor. By forming a layer made of S202 in the shape of a dot or dot, and coating the phosphor on the anode electrode provided with this S202 layer, the adhesion at the interface between the phosphor layer and the anode electrode is improved. It seems to be characterized by the fact that

〔Example〕

Next, the present invention will be explained in detail with reference to Examples.

FIG. 1 is a partial sectional view showing an embodiment of the present invention. First, a glass substrate is used as an insulating substrate 1, and this insulating substrate 1
An Al thin film is deposited thereon by ion sputtering, and power supply wiring 10 and anode electrode 1 are formed by photolithography.
1 was formed. Next, an insulating paste consisting of low melting point glass powder, coloring pigment, and organic binder was applied by screen printing, and baked at 580°C to a thickness of 25 μm.
An insulating layer 3 of m was provided. Next, apply S202 paste consisting of silicon oxide and an organic binder on the anode electrode 11 by 4
0.18 using 00 mesh stainless steel screen
Printed in a stripe shape with a line width of 0.08111 at wL pitch, baked at 550℃, and made into a stripe shape S with a thickness of 8 μm.
: An ot layer 21 was formed. Next, a phosphor paste consisting of a ZnO:Zn phosphor and an organic binder is applied to a part of the anode electrode 11 on which the KS202 layer is formed by screen printing, and dried at 150°C to form a 20 μm thick phosphor paste. Other parts K (Zn, Cd) S: Ay, C
A phosphor paste consisting of a type 1 phosphor and an organic binder was applied by screen printing and fired at 500° C. to form a phosphor layer (2) 62 with a thickness of 20 μm.

By arranging the grid 7 and the filament 8 at a position facing the display pattern 12 of the anode substrate obtained by the above operation, and sealing the anode substrate with the cover glass 13 provided with the conductive film, and sealing after evacuation. , manufactured a fluorescent display tube.

In the obtained fluorescent display tube, the striped S202 layer formed on the anode electrode increases the contact area with the phosphor layer, improving adhesion at the interface between the phosphor layer and the anode electrode. ZnO:Zn phosphor and (Zn, Cd)S;Ay,C in an impact test with a gravitational acceleration of 1.0OOG.
No peeling occurred in any of the 4-type phosphors.

In addition, although the anode electrode portion covered in a stripe shape with the S:02 layer does not directly interact with the phosphor coated on it, unevenness during light emission does not occur due to the lateral conductivity between the phosphor particles. Ta.

[Effects of the Invention] As explained above, the present invention forms a striped S202 layer on an anode electrode made of an Al thin film, and coats a phosphor on the anode electrode on which the S202 layer is formed. By coating and forming (Zn, Cd)S:A,! iF.

Even when a phosphor having a large particle size of 8 to 12 μm, such as a C4-based phosphor, is used, the phosphor layer has sufficient adhesion to the underlying anode electrode and will not peel off during the manufacturing process or product.

Further, the shape of the S:Ox layer is not limited to the stripe shape, and the same effect was confirmed even if the shape is a mesh shape or a dot shape.

Further, the method for forming the S:Ox layer is not limited to the screen printing method, and may also be formed by photophosphorography method or the like.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing the structure of the fluorescent display tube of the present invention. FIG. 2 is a cutaway perspective view of the fluorescent display tube. FIG. 3 is a partial cross-sectional view showing the structure of a conventional fluorescent display tube. 1...Insulating substrate, 3...Insulating layer, 7.
...Grid, 8...Filament, 1
0...--Power supply wiring, 11... Anode electrode,
12...Display pattern, 13...Cover glass, 14...Lead, 61...
Phosphor layer 1.62... Phosphor layer 2.21...
...Inventor II! I Kaya 31! I

Claims (1)

[Claims] A structure in which an anode electrode made of a thin Al film and a power supply wiring are formed on an insulating substrate, a phosphor is coated on the anode electrode in a display pattern, the electron bombardment from a filament causes the display to emit light, and the display is observed from the surface coated with the phosphor. A fluorescent display tube characterized in that a stripe-shaped, mesh-shaped, or dot-shaped SiO_2 layer is formed on the anode electrode, and a phosphor is coated on the anode electrode provided with the SiO_2 layer. .