JPS60175341A - Manufacture of fluorescent character display tube - Google Patents

Abstract

PURPOSE:To prevent generation of a crack due to impact or the like by assembling a fluorescent character display tube while performing vacuum exhaust through an exhaust pipe and sealing the exhaust pipe end part followed by forming a protective film made of fat or resin on said end part. CONSTITUTION:Each electrode such a grid, filament or the like is mounted on an anode substrate 1 coated with a phosphor 2 for being assembled while forming a container by mounting a translucent cover glass 3 with frit glass and vacuum exhausting through an exhaust pipe 4 followed by cutting the exhaust pipe 4 with a burner or the like for the purpose of airtight sealing. Next, the tip part 5 of the exhaust pipe is dipped into the fat 13 being heated and melted at about 150 deg. in a fat tank 11 including a heater 12 while being taken out in order to form a protective film which covers the tip 5a on the tip part 5 of the exhaust pipe with comparatively large thickness. Accordingly, generation of a crack or the like through impact on the exhaust pipe tip part by mishandling is excluded thus improving an yield.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for manufacturing a fluorescent display tube, and more particularly to a method for treating an exhaust pipe after evacuating an assembled fluorescent display tube. .

[Prior art]

Generally, when manufacturing a fluorescent display tube, each electrode such as a grid or filament is mounted on an anode substrate coated with a phosphor and assembled, and the assembled anode substrate and a translucent cover glass are fritted. A vacuum reactor is formed by hermetically sealing it with glass. Then, the vacuum is evacuated through an exhaust pipe made of glass provided on the side of the cover glass, and the exhaust pipe is hermetically sealed by cutting it with a gas burner, etc., and then the getter flash and terminals are connected. Fluorescent display tubes are manufactured through a process.

However, in conventional fluorescent display tubes manufactured in this way, a part of the exhaust pipe remains in a protruding state during the process of hermetically sealing the exhaust pipe, and its tip is structurally very weak. Become something. Therefore, cracks are more likely to occur when external shocks are applied, etc.
This crack causes a defect in the degree of vacuum inside the tube, resulting in a reduction in quality stability and yield.

[Summary of the invention]

The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and by forming a protective film made of oil or resin on the tip of the exhaust pipe after the exhaust pipe is hermetically sealed, it is possible to prevent external The present invention provides a method for manufacturing a fluorescent display tube that can protect the tip of the exhaust pipe from impact and prevent the occurrence of cracks. Embodiments of the present invention will be described below with reference to the drawings.

〔Example〕

Figures 1 to 3 are schematic process diagrams for explaining one embodiment of the method for manufacturing a fluorescent display tube according to the present invention. The steps up to this step are performed in the same manner as in the conventional method, as shown in FIG.

That is, in FIG. 1, first, each electrode such as a grid and filament is mounted and assembled on an anode substrate 1 coated with a phosphor 2 having a diagonal display pattern, and the anode after this assembly is completed. The substrate 1 and the transparent cover glass 3 are hermetically sealed with a frit glass (not shown) to form a vacuum container as a display tube. Next, the cover is
After evacuation is carried out through an exhaust pipe 4 made of glass attached to the side of the cylinder, the exhaust pipe 4 is cut with a gas burner or the like and hermetically sealed.

As a result, the exhaust pipe 4 remains with its tip 5 partially protruding, and its tip 5a has a conical shape as shown in FIG. In FIG. 1, reference numeral 6 indicates lead-out conductors formed on the sides of the anode substrate 1 in correspondence with the wiring patterns, and 7 indicates a frit glass for sealing the exhaust pipe 4 to the cover glass 3.

In the fluorescent display tube 10 that has been assembled in this way, the exhaust pipe tip 5 protrudes and the structure of the tip 5aFi becomes extremely weak. For this reason, as shown in FIG.
3. Dip it in the direction of the arrow and take it out. Then, as shown in FIG. 3, by holding the exhaust pipe tip 5 vertically and solidifying the oil attached to the tip 5 by natural cooling, a tip 5a is formed at the exhaust pipe tip 5. The protective film 15 made of oil and fat can be formed with a relatively thick film thickness.

In this way, the protective film 15 is installed on the structurally weak exhaust pipe tip 5.
The fluorescent display tube 10 is evacuated by depositing
The protective film 15 can alleviate shocks to the tip of the exhaust pipe due to handling errors that are likely to occur after the exhaust pipe 4 is hermetically sealed, and thermal shock to the solder cover when soldering a clip bottle. Therefore, as in the past, the exhaust pipe tip 5 is less likely to crack due to external impact, and thereby prevents a poor vacuum inside the pipe.
Quality stability can be improved by one yield.

Although the above-mentioned embodiment shows a case in which a protective film made of oil and fat is formed at the tip of the exhaust pipe, the present invention is not limited to this, and resin such as epoxy resin may be applied to the tip of the exhaust pipe. By curing this by UV irradiation or heating (approximately 150°C) to form a protective film with a thickness of approximately 0.5 mm), the tip of the exhaust pipe is subjected to an external impact in the same manner as described above. - It can also be protected from.

〔Effect of the invention〕

As explained above, according to the manufacturing method of the present invention, after the exhaust pipe of the evacuated fluorescent display tube is hermetically sealed, a durable protective film made of oil or resin is formed on the tip of the exhaust pipe. In addition, since the tip of the exhaust pipe can be protected from external impacts and cracks can be prevented, it is possible to improve quality stability and yield when manufacturing fluorescent display tubes. .

[Brief explanation of drawings]

1 to 3 are schematic process diagrams for explaining one embodiment of the method for manufacturing a fluorescent display tube according to the present invention. DESCRIPTION OF SYMBOLS 1... Anode substrate, 2... Fluorescent material, 3... Translucent cover glass, 4... Exhaust pipe, 5... Exhaust pipe tip, 6... - Leading conductor, 7 - Frit glass, 10 - e11 fluorescent display tube, 11 - Oil tank, 13 - Oil, 15 - Fist - protective film. Patent applicant: Ise Electronics Industry Co., Ltd. Agent: Masaki Yamakawa (L) 2 persons)

Claims (1)

[Claims] A step of evacuating a fluorescent display tube, which is formed by airtightly sealing an anode substrate on which predetermined electrodes are mounted and a translucent cover glass (by frit glass) through an exhaust pipe, and hermetically sealing the exhaust pipe. and a step of immersing the tip of the hermetically sealed exhaust pipe in heated and molten oil or coating with resin to form a retentive film on the tip of the exhaust pipe. A method for manufacturing a fluorescent display tube.