JP3056017B2 - Fluorescent display tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube, and more particularly to a fluorescent display tube having a small gap between segments.

[0002]

2. Description of the Related Art A conventional fluorescent display tube is shown in FIG.
As shown in (b), a power supply wiring (Al or Ag) 2 and a segment electrode (Al or Ag) 3 made of an Al sputtered film or Ag are formed on an insulating substrate 1 made of a glass substrate by photolithography (in the case of Al). ) Or a thick film printing method (in the case of Ag). Next, a first insulating layer 41 and a second insulating layer 42 having openings equal to or less than the area of the segment electrode (Al or Ag) 3 are sequentially applied and formed.

Next, the conductive layer 7 is filled in the openings of the first and second insulating layers 41 and 42, and the segment electrode (Al or Ag) is placed on the second insulating layer 42 via the conductive layer 7. 3 to be connected to a segment electrode (G) made of graphite.
r) Form 5. Further, the segment electrode (Gr)
The anode substrate obtained by coating and forming the phosphor layer 6 on the substrate 5 was used.

In this conventional anode substrate, the region of the gap between the adjacent segment electrodes (Gr) 5 is
Since the grooves had a thickness of 20 μm or more corresponding to the thickness of r), the conductive components that had oozed out during application of graphite or the phosphor were accumulated, and the structure was liable to cause a short circuit.

[0005]

In this conventional fluorescent display tube, as shown in FIGS. 2A and 2B, a phosphor layer 6 is formed on a segment electrode (Gr) 5 by coating.
When the segment electrode (Gr) 5 is applied (generally, screen printing), bleeding of a conductive component occurs between the adjacent segment electrodes (Gr) 5 and accumulates in a groove to exhibit an electrical short state, or a phosphor layer. 6 (generally screen printing).

The disadvantage is that the segment electrode (Gr) 5
The smaller the gap between them, the higher the probability of occurrence, and the limit of printing with the conventional structure without short-circuiting was that the gap between the segment electrodes (Gr) 5 was 0.22 mm and the gap between the phosphor layers was 0.34 mm. .

An object of the present invention is to provide a segment electrode (Gr).
Another object of the present invention is to provide a fluorescent display tube having a high yield without short circuit due to bleeding at the time of applying a phosphor layer.

[0008]

The present invention comprises an insulating substrate,
A first segment electrode made of Al or Ag formed on the insulating substrate and a power supply wiring;
An interlayer insulating layer having an opening on the first segment electrode;
A second segment electrode by graphite to be connected to the first segment electrode is formed on the interlayer insulating layer via a conductive layer filled in the opening, this second segment <br/> placement on the electrode in the fluorescent display tube having formed a phosphor layer, adjacent the second in the gap and a region between the segment electrodes provided upper insulating layer, and the upper-layer insulation layer surface of the height the second The height of the phosphor layer is suppressed to within 10 μm higher than the height of the surface of the segment electrode ;
Lower than the surface of the phosphor layer and the phosphor layer
On the inner surface of the second segment electrode separated from the second segment electrode.
Has a girder structure.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1A and 1B are a sectional view of a main part of an embodiment of the present invention and a partially enlarged plan view of a segment electrode thereof. As shown in FIGS. 1A and 1B, first, a power supply wiring (Al or Ag) 2 and a segment electrode (Al or Ag) 3 made of an Al sputtered film or Ag are formed on an insulating substrate 1 made of a glass substrate. Is formed by a photolithography method or a thick film printing method. Next, on the segment electrode (Al or Ag) 3, a first insulating layer 41 and a second insulating layer 42 each having an opening having the same or smaller area as the segment electrode (Al or Ag) 3 are sequentially formed. Then, the opening is filled with a conductive layer. Next, an adjacent segment electrode (Gr)
After the formation of the third insulating layer 43 in the region where the gap 5 is formed,
The segment electrodes (G
r) 5 is formed, and a phosphor is further applied thereon by screen printing to form a phosphor layer 6, thereby obtaining an anode substrate. By suppressing the height difference of the third insulating layer 43 to 10 μm or less, bleeding of the phosphor at the time of screen printing is prevented, and the phosphor layer 6 having a sharp outline can be obtained.

Next, a filament for emitting thermoelectrons, a grid for accelerating and controlling thermoelectrons, and the like are arranged on the anode substrate, sealed with a cover glass, and subjected to predetermined manufacturing processes such as exhaustion of exhaust gas. Obtain a fluorescent display tube.

[0012]

As described above, according to the present invention, an adjacent segment electrode (G) formed of graphite is used.
By providing a third insulating layer, which is higher than the surface of the segment electrode (Gr) by less than 10 μm, in a region serving as a gap of r), bleeding generated at the time of applying the segment electrode (Gr) and the phosphor layer is formed. This has the effect of preventing short shots and increasing the production yield of the fluorescent display tube.

Due to this effect, for example, the cap between the phosphor layers is 0.25 (mm) and the gap between the segment electrodes (Gr) made of graphite is 0.22 (mm).
Can be manufactured without problems in terms of yield.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view of a main part of an embodiment of the present invention and a partially enlarged plan view of a segment electrode thereof.

FIGS. 2 (a) and 2 (b) are a sectional view of a main part of an example of a conventional fluorescent display tube and a partially enlarged plan view of a segment electrode thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Power supply wiring (Al or Ag) 3 Segment electrode (Al or Ag) 5 Segment electrode (Gr) 6 Phosphor layer 7 Conductive layer 41 1st insulating layer 42 2nd insulating layer 43 3rd insulating layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 31/15

Claims (1)

(57) [Claims] 1. An insulating substrate, a first segment electrode made of Al or Ag formed on the insulating substrate, a power supply wiring, and an interlayer insulation covering the power supply wiring and having an opening on the first segment electrode. A second segment electrode made of graphite connected to the first segment electrode via a conductive layer formed on the interlayer insulating layer and filled in the opening; in the fluorescent display tube and a second segment electrode on the formed phosphor layer, an upper insulating layer provided in a region to be a gap between adjacent said second segment electrode, and the surface of the upper insulating layer The height of the second
The height of the segment electrode within 10 μm and lower than the height of the segment electrode , and lower than the surface of the phosphor layer,
The second cell in which the phosphor layer is separated from the upper insulating layer;
A fluorescent display tube provided on the inner surface of a segment electrode .