JPH0193033A - Fluorescent character display tube - Google Patents

Abstract

PURPOSE:To improve the electron emitting capacity of a cathode by connecting and solidifying a wiring coverage and a grid or a filament support without contacting a conductive adhesive to an insulating layer. CONSTITUTION:On an insulating layer 4 formed on a wiring coverage 2 of an anode substrate 1, an aperture 5' whose area is wider than a conventional one is formed, and inside the aperture 5', a pad 6' for connecting the wiring membrane 2 with a size almost equal to that of the aperture 5' is formed being exposed. And on the connection pad 6', a grid 3 is arranged attached by a conductive adhesive 7, and baked and solidified. By forming the aperture 5' of the insulating layer 4 in a large size, and the like, in such a way, the conductive adhesive 7 is prevented from adhering to the insulating layer 4. Consequently, the generation of a poisonous gas is suppressed, and the electron emitting capacity can be improved extensively.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fluorescent display tube, and in particular to electrically connecting a wiring film formed on an anode substrate and a grid or filament support using a conductive adhesive. This relates to the connection structure that allows

[Conventional technology]

Conventionally, in this type of fluorescent display tube, as shown in FIG. An opening 5 in an insulating layer 4 mainly composed of low melting point glass
On the connection pad 6 of the wiring film 2 exposed from the Ag
A conductive adhesive 7 made into a paste by mixing low melting point glass, pigment, and vehicle is applied.
Upper (C) The grid 3 is arranged and solidified by firing in the atmosphere at 400 to 500°C, and the grid 3 and the wiring coating 2 are electrically connected. Note that 8 is a low melting point for fixing the grid 3. It's glass.

In such an electrical connection configuration, the wiring coating 2 and the insulating layer 3 have a white (gray) color and a black color (black pigment is added to low melting point glass), respectively, and the contrast between the two is Utilizing this good quality, the application position of the conductive adhesive 7 can be easily recognized visually, and the application can be performed with high precision, and the amount of expensive Ag to be used can be optimized. Therefore, in the connection structure described above, the area of the opening 5 is reduced, and the conductive adhesive 7 is applied in contact with the insulating layer 4 over a large area. In this case, the conductive adhesive 7
If the applied area is small, the adhesive force will be low and the grid 3 will easily come off, so the conductive adhesive 7 is usually applied over a relatively wide area with a diameter of about 3 to 4++I11. Further, the locations where the conductive adhesive 7 is bonded depend on the number of grids 3, and are usually applied at several to several dozen locations.

[Problem that the invention seeks to solve]

However, the fluorescent display tube configured in this way is
Focusing on the low electron emitting ability of a cathode made of a filamentary oxide cathode coated with (Ba, Sr, Ca) O on the wire, we conducted an experiment to investigate the cause of this problem and found that the conductive adhesive 7 was insulating. It has been found that when coated in Layer 4, the cathode deteriorates significantly during tubing steps such as sealing and evacuation steps.

4 and 5 show the above-mentioned experimental results, and the horizontal axis represents the filament current I1. When the vertical axis shows the grid electrical work, as shown in Fig.
As shown in FIG. 5, the electron emitting ability of the cathode of tubes II and II is about one order of magnitude lower than that of tubes ① and ② in which the conductive adhesive 7 is applied on the anode substrate 1. It has been confirmed that when the conductive adhesive 7 is applied over the wiring wave M2 made of Ag, good cathode characteristics can be obtained as in the case where it is applied on the anode substrate 1.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a fluorescent display tube having six cathodes with improved electron emission capability.

[Means for solving problems]

The fluorescent display tube according to the present invention is one in which a wiring coating and a grid or filament support are bonded and solidified without bringing a conductive adhesive into contact with an insulating layer.

[For production]

In the present invention, by creating an adhesive structure in which the conductive adhesive does not come into contact with the insulating layer, the generation of harmful gases is suppressed and a decrease in cathode performance is prevented.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram of a grid attachment part for explaining one embodiment of a fluorescent display tube according to the present invention, in which (,) is a plan view, and (b) is a B of the same figure (,). An enlarged cross-sectional view taken along the line -B' is shown, and the same parts as in the previous figure are given the same reference numerals.

In the same figure, an opening 5' having a larger area than the conventional one and having a diameter of about 5 mm is formed in the insulator /@4 formed on the wiring film 2 of the anode substrate 1, and inside this opening rod there is a p2 'The connection pads C of the wiring film 2 having the same dimensions are exposed and formed. Then, on this connection pad C, there is a
The grid 3 is bonded and arranged with a conductive adhesive 7 in the normal range of 4H, and after being baked and solidified in the atmosphere at about 400 to 500°C, the tube is formed through the usual sealing process, exhaust process and aging process. is being produced.

In such a structure, the conductive adhesive 7 is prevented from adhering to the insulating layer 4 by forming the opening 5' of the insulating layer 4 to be large, and thus the fluorescent display manufactured in this way is The tube could be operated at a cathode temperature about 30°C lower than before.

FIG. 2 is a diagram of a grid attachment part showing another embodiment of the fluorescent display tube according to the present invention; FIG.
b) shows an enlarged sectional view taken along line B-13' of the same figure, in which the same parts as in the previous figure are given the same reference numerals. In the figure, the size of the opening 5 of the insulating layer 4 formed on the wiring film 2 is approximately the same as that of the conventional one (approximately Q, 5 rta"), and the surface of the insulating layer 4 is thick. Approximately 1000A
A barrier layer 9 made of about 10% of Sin is formed.

Then, on the opening 5 whose surface is covered with the barrier layer 9, a grid 3 having a diameter of 3 to 4 circles is adhered and placed with a conductive adhesive T, and heated at about 400 to 500° C. in the atmosphere. After being fired and solidified, the bulb is manufactured through the usual sealing, evacuation, and aging processes.

According to such a configuration, since the surface of the insulation r@4 is covered with the barrier layer 9, the insulation layer 4 of the conductive adhesive γ is coated with the barrier layer 9.
Since there is no adhesion to the cathode, there is no generation of harmful gases to the cathode9, and it is now possible to operate at a cathode temperature approximately 30°C lower than in the past.

Although it is not clear why the cathode deteriorates significantly only when the conductive adhesive 7 is applied over the insulating WI 4 in the above embodiment, the conductive adhesive 7 usually contains cellulose, etc. Contains organic binders,
When applied on the insulating layer 4, carbon residue tends to remain more easily than when applied on the anode substrate 1 and the wiring film 2. This carbon reduces PbO, Bρ8, which is a low melting point glass contained in the insulating layer 4, and is generated *Pb
, B are estimated to be deteriorating the cathode.

In addition, in the above-mentioned embodiment, a case was explained in which the grid was connected with a conductive adhesive onto the wiring film that was not exposed through the opening of the insulating layer, but when connecting the filament support onto the wiring film, there was no problem. It goes without saying that it can be applied in the same way and the same effect can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, since the conductive adhesive and the insulating layer are arranged in such a manner that they do not come into contact with each other, the electron emission ability of the cathode can be significantly increased compared to the conventional method, and the temperature can be lowered. Since the phosphor layer can be operated at low temperature, there is less B&D evaporated from the cathode and deposited on the phosphor layer, and the decrease in the luminous efficiency of the phosphor layer is reduced, resulting in a long life. Further, extremely excellent effects such as reduction in power consumption can be obtained at the same time.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are plan views of a grid attachment part showing an embodiment of a fluorescent display tube according to the present invention, taken along line B-B' of FIG.
FIGS. 2(a) and 2(b) are plan views of the grid mounting portion showing another embodiment of the fluorescent display tube according to the present invention; FIGS. Figure 3 (a),
(b) is a plan view of a grid attachment part of a conventional fluorescent display tube. An enlarged cross-sectional view of the B-B line, Figure 4 is a diagram showing the rise characteristics of the grid current with respect to the filament current in a tube in which conductive adhesive is layered on the insulating layer, and Figure 5 is a diagram showing the rise characteristics of the grid current on the anode substrate. FIG. 4 is a diagram showing the rise characteristics of grid current with respect to filament current in a tube coated with conductive adhesive. 1...Anode substrate, 2...Wiring coating, 3...
Grid, 4... Insulating layer, 5, 5'... Opening, 6, 6'... Connection pad, 7... Conductive adhesive, 8... Grid fixing. Low melting point glass for use, 9...
...Barrier layer. Patent Applicant: Ise Electronics Industry Co., Ltd. Agent Kazumi Yamakawa (eυ) 2 people) Figure 1 (0) (b) Figure 2 Figure 3 Figure 5 Fifmen ■Current If (mΔ)

Claims (1)

[Claims] A wiring coating and an insulating layer mainly composed of low-melting glass are laminated on an insulating anode substrate, openings are provided in required parts of the insulating layer, and the wiring coating exposed in the openings is connected to a grid or filament support. A fluorescent display tube obtained by bonding and solidifying with a conductive adhesive, characterized in that the conductive adhesive is bonded and solidified only to the wiring coating excluding the insulating layer and the grid or filament support. tube.