JPH0992184A - Fluorescent display tube and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable allocation and high densification of a display pattern to be freely realized on an anode board and eliminate wasteful consumption of energy. SOLUTION: On an anode board 7 constituted by forming a leading wire 2 and a display segment 6 on the surface of an insulating board 1, a control electrode 9, a support body of a filament 8, and lead pin 10 are fixed, and an anode board assembly 11 is formed. The first silver printed thick film 12 is formed at the top part opening end of a frame shaped spacer glass 13. The bottom part opening end of the spacer glass 13 is sealed at the peripheral edge part on the anode board assembly 11 by means of a flit glass 14. The anode board assembly 11 in which the spacer glass is sealed, the face glass 16, and a low-melting point metal body 17 are stored in their specified position in a vacuum chamber. The inside of the vacuum chamber is heated at a specified degree of vacuum, and the low-melting point metal body 17 is welded it between the first silver printed thick film 12 and the second silver printed thick film 15 and sealed.

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 no exhaust hole or exhaust tube in a vacuum container and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, when manufacturing a fluorescent display tube, various electrodes such as grids and filaments are mounted on an anode substrate coated with a phosphor and assembled, and the assembled anode substrate and translucent face. A vacuum container is formed by hermetically sealing glass and frit glass. Then, after performing vacuum exhaust through an exhaust pipe consisting of a glass valve provided on the side of the face glass and performing airtight sealing (chip off) of cutting this exhaust pipe with a gas burner or the like, a step of connecting the getter flash and terminals. After that, the fluorescent display tube is manufactured.

However, in the case of the pipe type fluorescent display tube having such a configuration, the outside of the vacuum container is 5 to 10 m.
Since the exhaust pipe projects with a length of m, the degree of freedom of arrangement is significantly impaired when the fluorescent display tube is mounted on the device.
Also, since the tip of this exhaust pipe is structurally extremely weak, cracks are likely to occur when external impact is applied, and the occurrence of these cracks reduces the degree of vacuum in the vacuum container. However, there is a drawback that the quality stability and the yield decrease.

As an improvement of such a drawback,
A chipless system is employed in which an exhaust hole is provided in the anode substrate, the exhaust hole is directly attached to an exhaust device, and the exhaust hole is closed by a metal or glass disk after the exhaust in the vacuum container is completed. The chipless fluorescent display tube thus configured is used as the best structure that complements the above-mentioned drawbacks of the pipe fluorescent display tube.

[0005]

However, the chipless type fluorescent display tube having such a structure has recently been required to be further downsized, and a display pattern formed inside the fluorescent display tube is required. There is a problem that there is no place to provide an exhaust hole in the anode substrate due to the arrangement of the above and the high density display pattern.

Further, as a problem common to both the pipe type and the chipless type fluorescent display tube, heating is performed up to a maximum temperature of about 480 ° C. in a sealing process using frit glass, and after cooling, it is heated to about 400 ° C. again in an exhausting process. There was a problem that doing was not negligible in terms of energy waste.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and its purpose is to:
It is an object of the present invention to provide a fluorescent display tube and a method of manufacturing the same that can freely arrange a display pattern on an anode substrate and realize a high density and can save energy.

[0008]

In order to achieve such an object, a fluorescent display tube according to the present invention comprises a control electrode and a filament on an anode substrate having lead wires and display segments formed on the surface of an insulating substrate. An anode substrate assembly having a support and lead pins formed thereon and a first opening at the upper open end.
And a frame-shaped spacer glass whose lower open end is sealed with frit glass at the peripheral edge on the anode substrate assembly, and a transparent silver-coated thick film at the inner peripheral edge. An optical face glass, a first silver-printed film formed on the upper open end of the spacer glass, and a second silver-printed thick film formed on the inner peripheral edge of the face glass are interposed between the inside of the tube. It is composed of a low melting point metal body that is vacuum-sealed, and it is possible to form a display pattern at an arbitrary position over a wide range on the anode substrate without using an exhaust pipe or an exhaust hole.

In addition, in the method of manufacturing a fluorescent display tube according to the present invention, a step of forming a positive electrode substrate assembly by fixing control electrodes, filament supports and lead pins on a positive electrode substrate having lead wires and display segments formed on its surface. When,
A step of forming a first silver-printed thick film on the upper opening end of the frame-shaped spacer glass; a step of sealing the lower opening end of the spacer glass on the peripheral edge part on the anode substrate assembly with frit glass; A step of forming a second thick silver printed film on the inner peripheral edge portion, a step of storing an anode substrate assembly having a spacer glass sealed therein, a face glass, and a low melting point metal body at predetermined positions in a vacuum chamber. And heating the inside of the vacuum chamber and maintaining a predetermined degree of vacuum, the first silver printed thick film formed on the upper open end of the spacer glass and the second silver printed formed on the inner peripheral edge of the face glass. The step of melting the low melting point metal body with the thick film and sealing the same makes it possible to form a fluorescent display tube that eliminates waste of energy and does not require an exhaust pipe or an exhaust hole.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of an essential part for explaining one embodiment of a fluorescent display tube according to the present invention. In FIG. 1, the lead wiring 2 of each electrode group is selectively formed on the surface of a base plate 1 made of, for example, a glass plate, and the insulating film 3 is coated on the entire surface of the base plate 1 including the lead wiring 2. Is formed. An anode 4 made of a conductive film is formed on the surface of the insulating film 3 so as to correspond to a desired display pattern. The anode 4 is connected to the corresponding lead wiring 2 via the insulating film 3. Through hole connected. Also,
A phosphor 5 is adhered and formed on the surface of the anode 4,
The display segment 6 is formed by the phosphor 5 and the phosphor 5 to form the anode substrate 7.

Further, at positions separated by a predetermined distance upward from the display segment 6 formed on the anode substrate 7, both ends in the longitudinal direction on the anode substrate 7 (front side and back side of the paper surface of the figure) are fixed. A linear filament 8 stretched between a pair of unillustrated filament supports is disposed,
Further, between the display segment 6 and the filament 8, electrically independent mesh-shaped control electrodes 9 are arranged for each digit. The anode 4, filament support, control electrode 9 and the like formed on the anode substrate 7 are electrically connected to one end side of the lead pin 10 by a conductive paste or welding, and the other end side thereof is the base plate 1. Anode substrate assembly 1 led out to the outside
1 is configured.

Further, on the anode substrate assembly 11, a spacer glass 13 made of a glass frame having a silver printed thick film 12 formed by applying a silver paste to the upper opening end.
The lower open end of the spacer glass 13 is sealed by a frit glass 14 together with a pair of leg portions of the filament support and a lead pin 10 which are not shown. Further, at the upper open end of the spacer glass 13, a transparent conductive film (not shown) is formed on the inner surface side, and a silver printed thick film 15 formed by applying silver paste on the inner surface side peripheral edge portion is provided. A face glass 16 is hermetically sealed via a frame-shaped low melting point alloy sheet 17, and the inside of the tube is vacuum-sealed to form a fluorescent display tube.

In this case, the mounting of the spacer glass 13 on the anode substrate assembly 11 and the mounting of the face glass 16 on the spacer glass 13 are performed in a vacuum chamber evacuated to a predetermined vacuum degree.

According to this structure, the anode substrate assembly 11 or the spacer glass 13 is provided with an exhaust pipe for vacuum exhaust,
It is possible to form a fluorescent display tube in which the inside of the tube is maintained at a predetermined vacuum degree without providing an exhaust hole.

Next, a method of manufacturing the thus-configured fluorescent display tube will be described with reference to the manufacturing apparatus shown in FIG. 2 and the process flow chart shown in FIG. First, the anode substrate 7 having the lead wiring 2, the insulating film 3, the anode 4, the phosphor 5 and the display segment 6 is formed on the base plate 1 described in FIG. 1 by a usual method. Next, after fixing a frame (not shown) for integrally supporting and fixing the filament 8 on the anode substrate 7, a frame integrally formed with the control electrode 9 and the lead pin 10 (step 101), the frit is attached to the peripheral portion of the anode substrate 7. (Step 10
2), calcination (step 103) is performed to form the anode substrate assembly 11 in which the frit glass 14 is temporarily fixed to the peripheral portion of the anode substrate 7.

Next, for example, a silver paste containing silver as a main component is printed on the upper open end of the frame-shaped spacer glass 13 (step 201) and calcined to form the silver-printed thick film 12 (step 202). Next, this spacer glass 13 is placed on the anode substrate assembly 11 to which the frit glass 14 has been fixed, and firing is performed (step 301), and the lower open end thereof is adhesively fixed (step 301).

In this case, the fixing with the frit glass 14 is carried out by fixing a pair of filament supports (not shown) disposed on the anode substrate 7, a support of the control electrode 9 and the lead pin 1.
It may be performed at the same time as fixing the frit such as 0.

Next, the face glass 16 explained in FIG.
After performing the NES processing on the inner surface side (step 401),
After cutting to a predetermined size (step 402) and washing (step 403), a silver paste containing, for example, silver as a main component is printed on the inner peripheral edge of the inner surface (step 404). Form the film 15 (step 40)
5).

Next, the low melting point metal sheet 17 described in FIG.
Is prepared by forming a eutectic alloy of silver and tin or a eutectic alloy of copper and tin having a melting point of about 430 ° C. into a frame shape (step 501).

Next, the anode substrate assembly 11 having the spacer glass 13 baked and fixed and the low melting point sheet 17 are temporarily fixed (step 302), and then set on a jig together with the face glass 16 (step 303). As shown in (4), the vacuum getter 20 is stored at a predetermined position in the vacuum chamber 21 (step 304).

Next, the vacuum system is operated, and while heating each component in the vacuum chamber 21 gradually (about 20 ° C./min) (step 305), the temperature is heated to about 480 ° C. to remove water molecules and gas molecules. Release enough. Here, after the inside of the vacuum chamber 21 reaches a certain degree of vacuum, constant heating (about 430 ° C./20 minutes) is performed, and a filament stretched over the anode substrate assembly 11 by operating a manipulator or the like (not shown). 8 is energized to decompose the carbonate applied to the surface of the filament 8 (step 30).
7).

Next, the manipulator is operated to heat and evaporate the vacuum getter 20 to form a getter film at a predetermined position on the inner surface side of the face glass 16 (step 30).
8). Further, the manipulator is operated to place the frame-shaped low melting point metal sheet 17 on the silver-printed thick film 12 formed at the upper opening end of the spacer glass 13. Although it depends on the melting point, it is desirable that the low-melting metal sheet 17 should be melted without special heating.

Further, by manipulating the manipulator, the face glass 16 is lowered and placed on the low melting point metal sheet 17 placed at the upper open end of the spacer glass 13 with the silver printed thick film 15 inside and at about 480 ° C. Heat (step 309) and press to seal (step 31)
0), press-bond and seal. Next, gradual cooling (about 20 ° C./min) is started (step 311), and when the temperature has dropped to an appropriate temperature, the chamber is taken out of the vacuum chamber 21 and a series of steps is completed.

[0024]

As described above, according to the present invention,
An extremely excellent effect as described below can be obtained. It is not necessary to provide an exhaust pipe or an exhaust hole in the face glass, the spacer glass, or the insulating substrate, and there are no restrictions in forming a mounting surface or a display pattern. Since the exhaust conductance, which has often been a problem in the past, can be made extremely large, it is extremely advantageous for shortening the exhaust time and ensuring quality after exhaust.

Since the sealing step and the exhaust step are performed in one heat step, waste of heat energy is eliminated,
It is advantageous in terms of energy. Nitrogen / carbon dioxide gas, which was required in the sealing step, is not required, which is advantageous in terms of cost. Since a low melting point metal is used instead of the frit glass for sealing the face glass and the spacer glass, it is advantageous in terms of gas generation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of an embodiment of a fluorescent display tube according to the present invention.

FIG. 2 is a diagram showing process steps for explaining one embodiment of a method of manufacturing a fluorescent display tube according to the present invention.

FIG. 3 is a perspective view of a manufacturing apparatus applied to the method of manufacturing a fluorescent display tube according to the present invention.

[Explanation of symbols]

1 ... Base plate, 2 ... Lead wiring, 3 ... Insulating film,
4 ... Anode, 5 ... Phosphor, 6 ... Display segment, 7 ... Anode substrate, 8 ... Filament, 9 ... Control electrode, 10 ... Lead pin, 11 ... Anode substrate assembly, 12 ... Silver printed thick film, 13
... Spacer glass, 14 ... Frit glass, 15 ... Silver printed thick film, 16 ... Face glass, 17 ... Low melting point alloy sheet, 20 ... Vacuum getter, 21 ... Vacuum chamber.

Claims (2)

[Claims] 1. A control electrode on an anode substrate formed by forming lead wiring and a display segment on the surface of an insulating substrate,
An anode substrate assembly having a filament support and a lead pin formed thereon, a first silver-printed thick film was formed on an upper opening end, and a lower opening end was sealed with a frit glass on a peripheral portion of the anode substrate assembly. A frame-shaped spacer glass, a light-transmissive face glass having a second silver-printed thick film formed on the inner peripheral edge thereof, and a first silver-printed film and a face glass formed on the upper open end of the spacer glass. Second formed on the inner peripheral edge
And a low melting point metal body which is interposed between the silver-printed thick film and which seals the inside of the tube in a vacuum, the fluorescent display tube. 2. The method of manufacturing a fluorescent display tube according to claim 1, wherein a control electrode, a filament support and a lead pin are fixed on an anode substrate having lead wires and display segments formed on the surface to form an anode substrate assembly. A step of forming a first thick silver-printed film on an upper opening end of the frame-shaped spacer glass, and a step of sealing the lower opening end of the spacer glass with a frit glass on a peripheral portion of the anode substrate assembly. A step of forming a second silver-printed thick film on the inner peripheral edge of the face glass, an anode substrate assembly having the spacer glass sealed therein, the face glass, and a low melting point metal body in a vacuum chamber. And storing it in a predetermined position, heating the inside of the vacuum chamber and maintaining a predetermined degree of vacuum, and forming the upper end of the spacer glass. Melting the low melting point metal body between the first silver-printed thick film and the second silver-printed thick film formed on the inner peripheral edge portion of the face glass to seal the metal body. Fluorescent display tube manufacturing method.