JPH023250B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an assembled front-type fluorescent display tube without an exhaust pipe in which an anode substrate, a side plate frame, and a flat plate are hermetically sealed in a vacuum, and a method for manufacturing the same.

The exhaust pipe of a fluorescent display tube is provided to protrude from the envelope in order to create a high vacuum atmosphere inside the hermetically sealed envelope. Various attempts have been made to create fluorescent display tubes without exhaust pipes, but no product has yet appeared.

In general, in conventional fluorescent display tubes, the cathode terminal part and the anode wiring conductor, which have large irregularities, are led out from the sealed part between the anode substrate and the side plate frame. It is necessary to apply a large amount of sealing material to seal the gap. For this reason, the anode substrate, which is the final sealing process of this type of fluorescent display tube,
In the step of vacuum firing and sealing the side plate frame to which the flat plate has already been sealed, the following problem occurs. That is, a large amount of organic compounds contained in the applied sealing material are decomposed and generated as carbide gas (eg, CO ₂ ), which is sealed in the envelope. The decomposed gas of this organic compound adheres to the oxide cathode in the envelope, and when the cathode is activated, it immediately sinters the cathode and acts as a harmful substance that inhibits the electron emission function of the cathode. This lowers the degree of vacuum within the envelope and contaminates the surface of the phosphor, significantly impairing the display characteristics of the fluorescent display tube.

In addition, due to the unevenness of the anode wiring conductor and the cathode terminal, air leaks from between the anode substrate and the side plate frame into the envelope, making it difficult to maintain a high vacuum inside the envelope. Therefore, it was difficult to exhibit the display characteristics.

To solve the above-mentioned problems, the cathode terminal part should be made thinner to minimize unevenness, and the sealing area between the anode substrate and the side plate frame should be a plane-to-plane bond to reduce the amount of sealing. It would be possible to seal the two together with a material, but since the cathode terminal portion is joined to the cathode support fitting, it is difficult to make the film thin.

Therefore, the present invention has been made in view of the above points, and the terminal portion of the cathode is sandwiched between the plane plate and the side plate frame body and fixed with a glass sealing material, and the terminal part of the cathode is sandwiched between the side plate frame body and the anode substrate. During this process, a part of the sealed part of the side plate frame sandwiched the wiring conductor of the anode formed of a conductive thin film and fixed it with a glass sealing material, thereby preventing the decomposition gas of organic matter from being released in the final sealing process. A method for manufacturing a fluorescent display tube without an exhaust pipe, which is extremely unlikely to occur and which can significantly improve the display characteristics of the fluorescent display tube by preventing air leakage into the envelope and maintaining it in a high vacuum atmosphere. The purpose is to provide.

Therefore, in order to achieve this object, the method for manufacturing a fluorescent display tube according to the present invention includes depositing a conductive thin film on a substrate made of an insulating material, and then forming an anode conductor and a wiring conductor by photo-etching. a step of making an anode substrate; a step of depositing a phosphor on the anode substrate; and placing at least a terminal portion of the cathode on a flat plate forming an envelope together with the anode substrate, and sandwiching the terminal portion. After joining one side of the side plate frame body to the plane plate using a sealing material, a sealing material is applied to the other end surface of the side plate frame body, and the sealing material is prepared in a vacuum. a step of firing to remove gas from the sealing material;
A step of bonding and fixing a support fitting to which at least a filament-shaped cathode is attached to the terminal portion, cutting and removing an unnecessary portion of the support fitting, and a surface of the other end of the side plate frame to which the flat plate is bonded. The method further comprises the steps of assembling and stacking the anode substrates, evacuation in a vacuum, and main firing in a vacuum to seal the anode substrate and the side plate frame with the sealing material. There is.

Hereinafter, a method for manufacturing a fluorescent display tube according to the present invention will be explained with reference to an embodiment shown in the drawings.

FIG. 1 shows an example of the manufacturing process of a fluorescent display tube 1, which is a type in which the display is observed from the flat plate side and uses a static drive method, and FIG. 2 is a flowchart of the manufacturing process. It is.

In FIG. 1, reference numeral 1 denotes an anode substrate, which is a flat plate made of an insulating material such as glass or ceramic. A thin metal film is formed on the inner surface of the anode substrate 1 by a physical method such as sputtering or vapor deposition of a conductive metal such as aluminum. Unnecessary portions of this metal film are removed by, for example, a photo-etching method, and as shown in FIGS. , anode conductor 2a
A planar control electrode 2c is formed around the wiring conductor 2b and separated from both conductors.
The wiring conductor 2b of each anode conductor 2a is led out to the upper and lower ends of the anode substrate 1 and connected to an external terminal portion 2d. As shown in FIG. 1B, phosphors 3 are deposited on the anode conductors 2a of the anode substrate 1 having the above-mentioned patterns by thick film printing or electrodeposition.

On the other hand, the flat plate 4 is formed of a light-transmitting or light-scattering insulating material, such as glass, as shown in FIG. 1C, and the vertical width d of the flat plate 4 is
It is smaller than the vertical width D of the substrate 1, and the horizontal width l of the flat plate 4 is approximately equal to the horizontal width L of the substrate 1, and a transparent conductive film is formed on the inner surface of the flat plate 4. 5 is formed by adhesion. Further, the side plate frame body 6 interposed between the anode substrate 1 and the flat plate 4 has a size that is approximately the same as that of the flat plate 4, and is similar to the flat plate 4 as shown in FIG. 1D. It is assembled into a rectangular shape by upper and lower frames 6a, 6b and left and right frames 6c, 6d molded from a material. Further, the electrode frame 7 for a cathode support fitting held between the side plate frame body 6 and the plane plate 4 has a rectangular outer frame 7a.
, four auxiliary terminals 7c, and terminal portions 7d, 7e, 7 for leading out the cathode support fittings 9, which will be described later.
f, 7g, and is formed thin.
Further, if necessary, an inner frame may be provided to connect each terminal portion and the intermediate portion of the auxiliary terminal.

After applying the sealing material R of crystalline glass to the side plate frame 6 and the plane plate 4, the electrode frame 7 is sandwiched between the side plate frame 6 and the plane plate 4, and the electrode frame 7 is placed in the air. In the firing temperature C ₁ , for example C ₁ = 450~
By heating and firing at 550℃, crystalline glass becomes crystallized. Therefore, the remelting temperature of the fired crystalline glass increases and it does not remelt at the subsequent sealing temperature, and the three are integrated as shown in FIG. 1E, and then the above electrode The frame 7 has terminal portions 7d and 7 as shown in FIG. 1F.
Unnecessary portions are cut off leaving the portion e, and the tip portions 7h of the terminal portions 7d, 7e, 7f, and 7g are erected.

Incidentally, the tip portion 7h may be erected from the beginning. Further, the electrode frame 7 has a thin wall thickness, and the slight gap between the flat plate 4 and the side plate frame 6 is completely hermetically sealed by the sealing material R of crystalline glass.

Next, as shown in FIG.
Support members 9a and 9b to which both ends of the cathode 8 are fixed
and connecting members 9c, 9c that connect and hold the opposing ends of the supporting members 9a, 9b.
Note that the supporting members 9a, 9b and the connecting members 9c, 9
The four connection parts with c are the terminal parts 7d, 7
Contact 9 connected to the tip 7h of e, 7f, 7g
d, and the vertical and horizontal widths of the support fittings 9 are smaller than the vertical and horizontal inner widths of the side plate frame body 6. Before attaching the support fitting 9 to the space formed by the side plate frame 6 and the plane plate 4, a sealing material S of amorphous glass, for example frit glass, is applied to the upper end surface of the side plate frame 6 in a corrugated shape. Print stickers. Then, the sealing material S is fired in the atmosphere at a firing temperature of, for example, 450° to 550°C to oxidize the solvent and binder in the amorphous glass sealing material S and exhaust the decomposed gas, and then Near the melting point of amorphous glass (400℃~600℃)
℃) for about 1 to ₂ hours to remove the gas contained in the amorphous glass sealing material S. Note that the remelting temperature of the sealing material R has increased due to crystallization, and the firing temperature _C2 of the sealing material S is set as high as the firing temperature _C1 of the sealing material R. Also, since the sealing material R of crystalline glass has already been crystallized, there is no risk that the sealing material R will melt, and therefore the bonding state between the flat plate 4 and the side plate frame 6 will be inhibited. There is no.

After this vacuum preliminary firing is completed, the support fittings 9 are attached. The support fittings 9 are attached to the side plate frame body 6
After each contact 9d fitted into the space of the flat plate 4 is fixed to the four electrodes 7 by welding or the like, the first
Connection members 9c, 9 that are no longer needed as shown in Figure H
c is cut and removed from the upper position of the contact point 9d.

Next, the anode substrate 1 and the side plate frame 6 in which the cathode 8 is installed and the flat plate 4 is sealed are shown in FIG.
Then, they are assembled as shown in Figure 1 J, and heated and sealed in a vacuum while applying pressure from above and below to form an envelope, completing a fluorescent display tube without an exhaust tube that can be observed from the flat plate 4 side. be done. Specifically, after assembly, an evacuation operation is performed using the gap between the corrugated amorphous glass sealing material S of the side plate frame 6 and the anode substrate 1 in a vacuum such as in a bell jar. ,
The flat anode substrate 1 and the side plate frame 6 are sealed together by vacuum main firing at a firing temperature _C3 , for example, 300 to 500°C. At this time, the anode substrate 1 and the flat plate 4 are subjected to stress from above and below, and the sealing material S melts, improving the flatness of both sealing parts, and furthermore, the wiring conductor 2b on the substrate 1 is a peritoneal membrane, In addition, since it is compatible with the sealing material S, the substrate 1 and the side plate frame 6 are reliably hermetically sealed without any unevenness. Further, the activation treatment of the cathode 8 is carried out under appropriate conditions immediately before or after sealing. Further, after sealing, gettering is performed, and as shown in FIG. 1J, FIG. 4, and FIG. The wiring conductor 2b is led out above and below the display tube main body. The external terminal 2d arranged at the end of the wiring conductor 2b has a
If necessary, lead pins may be attached by soldering or the like.

In the above-described embodiment, the cathode 8 was stretched after the vacuum pre-baking of the sealing material S made of amorphous glass, that is, after the organic decomposition gas of the sealing material S made of amorphous glass was completely exhausted. Since the supporting metal fittings 9 are attached by welding and then fired in a vacuum, no organic decomposition gas is generated when the vacuum final firing is completed and the sealing is completed, and when the cathode 8 is activated, the cathode 8 is sintered (baked) by the organic decomposition gas. (Conclusion) Not only is there no risk of decomposition, the degree of vacuum within the envelope will not decrease, and the phosphor 3 will not be affected by organic decomposition gas at all, and the life of the cathode 8 can be extended. You can also increase the brightness. Also,
Needless to say, since an exhaust pipe is not required, impact resistance is good and miniaturization is easy.

Furthermore, since the terminal portions 7d and 7e of the relatively thick electrode frame 7 connected to the cathode 8 are attached in advance between the plane plate 4 and the side plate frame 6,
There is no need to attach it between the anode substrate 1 and the side plate frame 6 as in the conventional case, and the wiring conductor 2b sandwiched between the anode substrate 1 and the side plate frame 6 is formed of a thin film. The anode substrate 1 and the side plate frame 6 can be flattened and sealed with good adhesion, and there is no risk of air leaking into the envelope in a high vacuum atmosphere.

What has been described above is the first embodiment of the present invention. Next, the second embodiment of the present invention will be explained with reference to FIGS. 6 and 7. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

The fluorescent display tubes shown in FIGS. 6 and 7 are front-emission type fluorescent display tubes in which the display is observed from the anode substrate 101 side, and the substrate 101 is insulating and transparent like the first embodiment. The anode substrate 101 has conductive metal such as Al, Ni, Cr, Au, etc. on the inner surface of the anode substrate 101.
In this embodiment, a part of Al is applied to the anode conductor 102a and its wiring conductor 102b by a physical method such as sputtering or vapor deposition.
A thin metal coating 102 is formed.
The metal film of the seven-segment anode conductor 102a is partially removed by photoetching, and the anode conductor 102a is formed into a mesh shape or a comb-like shape having minute gaps 102c. A phosphor 103 is adhered to the anode conductor 102a as shown in FIGS. 7 and 6B. Note that an insulating layer 110 is formed on the anode substrate 101 except for the metal film 102, and the phosphor 103 extends from the anode conductor 102a to the insulating layer 110.

On the other hand, in the same manner as in the first embodiment, the flat plate 104 on which the transparent conductive film 105 is formed and the side plate frame 106 are baked with the electrode frame 107 sandwiched between them and the sealing material R of crystalline glass. Temperature _C1 (450~550℃)
It is integrated by heating and firing. The electrode frame 107 has terminal portions 107d, 107e, 1
It was cut and removed leaving 07f and 107g.

At this point, the amorphous glass S is printed in a waveform on the upper surface of the side plate frame body 106, and after being fired in the atmosphere at a firing temperature of C ₁ (450 to 550°C), the firing temperature is C 1 in a vacuum. ₂ (C ₂ <C ₁ , 400-500°C).

Next, the cathode support fitting 109 on which the cathode 108 is stretched is fitted, and its four contacts 109d are connected to the corresponding electrodes 107h, 107i, 107.
j, 107k and welded together, the unnecessary connecting member 109c of the support fitting 109 is cut and removed. Furthermore, a mesh-shaped control electrode 1
The support fitting 130 of the control electrode on which the control electrode 20 is stretched has the same shape as the support fitting 109, and its vertical width V is the same as that of the support fitting 109, and the horizontal width W is smaller than that of the support fitting 109. In addition, this support metal fitting 130
Contact points 130a are provided at the four corners of , protruding downward. Therefore, the support fitting 130
is fitted above the cathode 108 and each contact 1
Electrodes 107l, 107m, 10 to which 30a corresponds
7n and 107p and are welded, the unnecessary supporting member 130b of the supporting metal fitting 130 is cut and removed. In this case, the control electrode 120 is positioned and fixed without coming into contact with the cathode 108 because the contact point 130a is formed to protrude downward.

In this way, the side plate frame 106 has the cathode 108 and the control electrode 120 attached as shown in FIG. 6D.
The anode substrate 101 is attached with the phosphor 103 facing inside. That is, after evacuation is performed in a vacuum, the firing temperature is changed to _C3 (300 to 500℃) ( _C3
<C ₂ ), the sealing material S on the side plate frame body 106 is subjected to vacuum firing, and the substrate 101 is sealed.

Thus, a front emission type fluorescent display tube having a mesh-shaped control electrode as shown in FIGS. 6E and 7 is completed.

Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the cathode support fitting and the control electrode support fitting in the second embodiment are integrated, and the cathode 308 and the control electrode 320 stretched over the support fitting 309 are fixed. The contacts 309a on the control electrode 320 side are provided so as to protrude downward.

After the sealing material S is vacuum pre-baked on the side plate frame 206, the contact 3 of the control electrode 320 is
09a are terminal parts 207d, 207e, 207 respectively
f, 207g electrode 207l, 207m, 207
n, 207p, and the contact 308a on the cathode 308 side is welded to each electrode 207h, 207i, 2
07j and 207k, and then the unnecessary supporting member 309c is cut and removed.

In the above-mentioned embodiments, the substrate pattern is a static drive pattern, but if the control electrodes are electrically divided for each display area in the embodiments shown in FIGS. 6 and 8, a dynamic drive type fluorescent display tube can be obtained. Of course, it will be. Furthermore, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications without changing the gist thereof.

As described above, according to the method for manufacturing a fluorescent display tube according to the present invention, at least the terminal portion of the cathode is placed on a flat plate, and the side plate frame is sealed with a sealing material with the terminal portion sandwiched therebetween. After joining, a sealing material is applied to the other end surface of the side plate frame body, and after degassing the other sealing material by vacuum pre-firing, at least the support metal fitting for the cathode is attached to the terminal portion. The adhesive and unnecessary parts are cut and removed, the other end of the side plate frame body and the anode substrate are overlapped, and the anode substrate is evacuated and fired in a vacuum to seal and seal them. In addition to improving the display characteristics and extending the lifespan of the display tube by eliminating contamination and contamination of the phosphor, the thick cathode terminal can be sealed between the flat plate and the sides in the atmosphere using a large amount of sealing material. Since it can be attached between the face plate frames, the attachment work is easy and the terminal portion can be firmly attached. Furthermore, according to this manufacturing method, there are almost no inclusions between the side plate frame and the anode substrate, and each sealing portion of the side plate frame and the anode substrate is removed in the final sealing process performed in a high vacuum atmosphere. By flattening the display tube and using a small amount of sealing material, ideal sealing can be achieved.This prevents air leakage into the display tube envelope, which conventionally occurs during the final sealing process, and improves the quality of the display tube after manufacturing. It is possible to eliminate leakage mistakes, maintain a high vacuum inside the display tube envelope to improve display characteristics, and stably manufacture display tubes without exhaust pipes, which was previously difficult. There is an effect that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a process explanatory diagram showing the manufacturing process of a fluorescent display tube according to the first embodiment of the present invention, FIG. 2 is a flowchart of the same manufacturing process, and FIG. An enlarged view of the board, FIG. 4 is a front view of a fluorescent display tube of the type observed from a completed flat board,
5 is a sectional view taken along the - line in FIG. 4, FIG. 6 is a process explanatory diagram showing a part of the manufacturing process of a fluorescent display tube according to the second embodiment of the present invention, and FIG. FIG. 8, which is a sectional view of the completed front-emitting type fluorescent display tube, is an exploded perspective view showing a third embodiment of the fluorescent display tube according to the present invention. 1,101... Anode substrate, 2a, 102a...
Anode conductor, 2b, 102b...Wiring conductor, 2c,
120...control electrode, 3,103...phosphor,
4,104... Plane plate, 6,106... Side plate frame, 7,107... Electrode frame, 8,108...
... Cathode, 9,109 ... Cathode support fitting, 130
... Supporting metal fitting for control electrode, 309... Supporting metal fitting for cathode and control electrode, R... Sealing material for crystalline glass,
S...Sealing material for amorphous glass.

Claims (1)

[Claims] 1. A step of forming an anode substrate by forming an anode conductor and a wiring conductor by photoetching after depositing a conductive thin film on a substrate made of an insulating material, and depositing a phosphor on the anode substrate. A step of placing at least a terminal portion of a cathode on a flat plate forming an envelope together with the anode substrate, and attaching the flat plate to one side of the side plate frame with a sealing material with the terminal portion in between. After joining, a sealing material is applied to the other end surface of the side plate frame body,
A step of preliminary baking the sealing material in a vacuum to remove gas from the sealing material, and a step of bonding and fixing a support fitting to which at least a filament-shaped cathode is attached to the terminal portion, thereby eliminating unnecessary use of the support fitting. A step of cutting and removing a portion, assembling and overlapping the anode substrate on the other end surface of the side plate frame body to which the flat plate is joined, evacuation in a vacuum, and main baking in a vacuum to form the sealing material. 1. A method for manufacturing a fluorescent display tube, comprising the step of sealing an anode substrate and a side plate frame body together. 2. A crystalline glass sealant is used to seal the plane plate and the side plate frame, and an amorphous glass sealant is used to seal the side plate frame and the anode substrate. A method for manufacturing a fluorescent display tube according to claim 1, wherein the fluorescent display tube is sealed with a material. 3. The vacuum pre-firing temperature of the amorphous glass sealing material is set higher than the vacuum main baking temperature of the amorphous glass sealing material. Production method.