JPS6171533A - Method of manufacturing display tube - Google Patents

Abstract

PURPOSE:To carry out a through production by mounting a container on a substrate provided with an anode having a phosphor layer and an electrode such as a cathode etc., and also mounting a cover portion on an exhaust hole, respectively, through oxide solder, and transporting it to carry out the enclosing and the sealing. CONSTITUTION:A phosphor layer 6 is provided on the anode conductor 4 on a substrate 1, and a control electrode 13 and a filamentary cathode 14 are opposed to it, and a container 11 is mounted on the substrate 1 through oxide solder 10, and a cover member 17 is also provided on an exhaust hole 5 through oxide solder 16, and a fluorescent display tube 15 is tentatively assembled. And the fluorescent display tube which is tentatively assembled is continuously transported to each process through a preliminary burning chamber 20, a gas displacing chamber 22, an enclosing furnace 25, a slow cooling chamber 27, a loose vacuum chamber 28, a tight vacuum chamber 33, a sealing chamber 34, a cooling chamber 38 and a bringing out chamber 40 by means of a transporter to carry out the enclosing and the sealing. Accordingly, it is possible to achieve the through production system of an in-line type to improve the productivity and the quality by providing a processing chamber every process.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to display tubes used in display devices for home appliances, cars, watches, computer terminals, games, etc. This invention relates to a method of manufacturing a chipless display tube without a chip tube for exhaust.

Conventional display tubes having chip tubes include discharge type display tubes, plasma displays, fluorescent display tubes, etc., and the present invention will be described below with respect to fluorescent display tubes.

[Conventional technology and its problems]

A fluorescent display tube has an anode, a control electrode, a filament cathode, etc. arranged inside an envelope made of an insulating material. All gases are sucked and exhausted through the exhaust holes.

In other words, a chip tube made of a glass tube is installed protruding from the exhaust hole, and when the chip tube is evacuated and the inside of the envelope reaches a high vacuum state, the chip tube is melted and closed to create a high vacuum inside the envelope. Keep it up my friend. This process is called a sealing process.

However, since the chip tube protrudes from the envelope after being sealed, it not only has a negative space factor when attaching the display tube to a display device, but also has poor durability because the chip tube is made of glass. It has the problem of being weak against shock, so in recent years,
Nowadays, so-called chipless fluorescent display tubes are required.

Therefore, a known example of a conventional chipless fluorescent display tube is Utility Model Publication No. 58-10291. As shown in FIG. 4, this fluorescent display tube has a glass substrate A constituting the envelope.
A through hole Bt is formed in the through hole B, and a ceramic member Dt is fixed to the inner surface of the through hole B with a 7-litre glass C. This ceramic member DK is provided with a small diameter through hole Et approximately coaxially with the through hole B, and a transparent A metallized layer Ft is formed on the inner surface of the hole E and the surface of the skin portion of the ceramic member exposed from the through hole B around the through hole E, and a brazing material G is placed around the periphery of the through hole 8 to form an outer circumference. After the inside of the container is evacuated, the entire vicinity of the through hole E is heated to melt the brazing material Gt, thereby sealing the envelope.

However, the above-mentioned envelope has disadvantages such as a complicated structure and a cause of deterioration of characteristics, so that it has not been put into practical use yet.

MayuThe conventional manufacturing method for chipless display tubes is a batch-type manufacturing method in which a large number of envelopes are placed in a vacuum chamber such as a Pel Jar, and the inside of the Pel Jar is heated for a predetermined period of time to seal it. There is a method known in Japanese Patent Application Laid-Open No. 52-45865.

This conventional batch-type manufacturing method has the disadvantage that there is a limit to the number of pieces that can be produced in one batch, and that each batch is sucked into a high vacuum, then returned to the atmosphere, and all the atmospheric gas in the furnace is pumped out. Shi7? However, since the temperature is raised and the temperature is lowered, the following problems arise.

(1) Batch-type systems are difficult to fully automate in many areas, and productivity per unit of time is poor.

(2) Various production conditions such as temperature conditions, vacuum conditions, atmospheric gas conditions, etc. may change from batch to batch, and it may not be possible to produce uniform products.

(3) Each batch is evacuated and atmospheric gas is introduced into the chamber for sealing, and it is exhausted during the sealing process and product removal process, so there is a waste of atmospheric gas and thermal energy.

(4) After completing the sealing process by heating each batch, the inside of the furnace including the products and jigs to cool and solidify the oxide solder is cooled down, and the products are taken out. There is a waste of heat energy because there is nine.

(5) Sealing! - It takes a long time to set the processing conditions such as heating time and suction time for each batch, starting from room temperature and pressure until the stopping conditions are reached. It didn't go up.

[Purpose of the invention]

This invention was made in view of the above circumstances, and
In other words, it is easy to automate, rationalize, improve efficiency, and save labor in the manufacturing method of display tubes, which increases productivity, makes products more uniform, and eliminates waste such as atmospheric gas, heat, and exhaust time. The purpose of the present invention is to provide a method of manufacturing a Shishitube that is possible.

[Structure of the invention]

Ninth, to achieve all of the above objects, the method for manufacturing a display tube of the present invention comprises forming an electrode such as a filament-shaped cathode on an insulating substrate, facing the anode and the anode with a phosphor layer disposed on the anode conductor. An airtight envelope is constituted by the interposed electrode substrate and a container portion that covers the electrodes and is sealed to the periphery of the anode substrate with oxide solder. In the method for manufacturing a display tube, the exhaust hole is sealed with a lid member to form a specific atmosphere including a vacuum atmosphere inside the envelope. A step of pre-firing the phosphoric oxide solder applied to one side, a step of replacing the inside and outside of the envelope with an inert gas atmosphere, and a step of heating and sealing the anode substrate and the container part in an inert gas atmosphere. a step of slowly cooling the sealed envelope, a rough drawing step of forming a low vacuum atmosphere inside the envelope, and a main drawing step of forming a high vacuum atmosphere inside the envelope. , a step of closing and sealing the exhaust hole by heating the lid member in a vacuum atmosphere or a specific gas atmosphere, a step of cooling the sealed display tube, a step of taking out the vacuum fit-leak of the take-out chamber, and a step of sealing the exhaust hole by heating the lid member in a vacuum atmosphere or a specific gas atmosphere. It is characterized in that it has a processing chamber for each process, and the envelope is transferred to each process chamber by a transfer device to perform continuous integrated production.

[Embodiments of the invention]

The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a sectional view of a fluorescent display tube manufactured by the manufacturing method of the present invention. Reference numeral 1 denotes an anode substrate, which is a substrate made of glass or ceramics having L-insulating properties. A wiring conductor 2 made of a conductive metal such as silver or aluminum is disposed on this substrate. The wiring pattern is formed by a suitable method such as a thick film printing method, a thin metal film formed by a thin evaporation method, and then a photolithography method to form the entire wiring pattern.

F
ell! The 3R layer 3 is applied by thick film printing.

This insulating layer 3 is provided with a through hole portion 3a, and a carbon film is formed on the through hole portion 3a. The wiring conductor 2 and the anode conductor 4 are electrically connected by disposing the anode conductor 4 as the main component and filling the through-hole portion 3&.゛Furthermore, on this anode conductor 4, a phosphor layer 6 is printed using a full-thick film printing method,
It is disposed by an appropriate method such as a precipitation method or an electrodeposition method.

(191) In the fluorescent display tube of the present invention, the exhaust hole 5 is provided in a part of the envelope 15, and in the case of this embodiment, the exhaust hole 5 is provided in the anode substrate 1. The exhaust hole 5 may be formed not only in the anode substrate 1 but also in the side plate 9 or the front plate 7, which will be described later.

A cover member 17 is bonded to the anode substrate 1 with an oxide solder 16 to close the exhaust hole 5 and seal the envelope 1st.

A mesh-shaped control electrode 13 is provided on the spacer frame 12 on the upper surface of the anode substrate 1, facing the phosphor layer 6, and a plurality of filament-shaped cathodes 14'' are spaced apart above the mesh-shaped control electrode 13. It is a nine-structure structure with a t'' tension frame.

Thus, the phosphor layer 6 and the control electrode structure 3 are formed on the anode substrate 1.
A front container 11 made of glass or ceramics containing electrodes such as the cathode 14 is bonded and sealed with an oxide binder 10. In this way, the substrate 1 and the front container 11t
- The process of bonding to form an envelope is called total sealing. The front container 11 is formed into a box shape by adhering the side panels 9t and oxide glue 8 to the four peripheries of the front panel 7 having translucent properties.

Next, the method for manufacturing a display tube of the present invention will be explained by taking a fluorescent display tube as an example, with reference to an explanatory diagram of a mounting device in FIG. 2 and a flowchart showing the manufacturing method in FIG.

As shown in FIG. 3, the anode substrate 1 is first made by drilling a through hole in a corner of the anode substrate 1 with a diamond drill or the like to form an exhaust hole 5t. Note that the exhaust hole may be provided in an envelope other than the anode substrate. After the anode substrate 1 provided with the exhaust hole 5t is cleaned, a wiring conductor 2 made of silver paste is attached.
For example, a wiring pattern is formed by applying the paste using a screen printing method and then baking it to remove the evaporated components in the paste.

Next, an insulating layer 3 is formed on the wiring conductor 2 by printing and baking a paste containing low melting point frit glass as a main component. This insulating layer 3 is provided so as to form a through hole portion called a through hole 3&. The through pole 3a is provided on the wiring conductor 2.

Next, an anode conductor 4'ff is laminated and arranged on this through hole 3a. The anode conductor 4 is formed by printing and firing nine pastes mainly composed of carbon.

Since the through hole 3a is also filled with the anode conductor 4, the anode conductor 4 is electrically connected to the wiring conductor.

Next, a phosphor layer 6 is entirely deposited on the anode conductor 4 by a printing method and then fired to complete the anode substrate construction.

The front plate 7 is coated with a material for a transparent conductive film such as Nesa film and fired in the atmosphere to form a transparent conductive film.

Next, the oxide solder 8 and the oxide solder 8t are applied around the front plate 7, and the side plates 9 are adhered to the four sides of the periphery of the companion front plate 70, thereby assembling the box-shaped container portion 11.

Then, the side plate 9 is fixed to the front plate 7 by firing to form the container portion 11t.

Next, apply oxide solder 10t to the lower end of the side plate 9, which is the open end of the container part 11 and the sealing surface with the anode substrate 1. It is applied by a printing method and then dried to completely evaporate the organic solvent etc. to complete the container part.

In addition, for the spacer frame ratio, if necessary, the mesh-like control electrode is fully welded and attached.

Further, a fixing member for attaching the filament-shaped cathode is welded and fixed to the spacer frame 12, and the filament-shaped cathode is welded to this fixing member.

Furthermore, the lid member 17 is formed of the same glass piece or metal piece as the anode substrate 1, and an oxide solder 16 is applied to the surface facing the envelope 15, and air is removed by pre-baking. I'll do everything.

Completed through the above steps, the next electrode substrate 1, container portion 11, spacer frame n, and lid member 17' are assembled into an envelope assembly: set in a vertical sealing jig. First, place the spacer frame 12t on the anode substrate 1, cover the front container 11 over it,
A cover member 17 is installed below the exhaust hole 5.

The assembly and sealing jig in which the members constituting the envelope 15 are set is entered from the preliminary firing chamber of the integrated continuous production equipment (in-line equipment) for sealing and sealing soil shown in Fig. 2, and finally taken out from the removal chamber. When the envelope 15 is removed from the housing, the envelope 15 is sealed and the lid member 1
7, the inside of the envelope can be maintained in a high vacuum state.

In this continuous integrated production system, a plurality of process-specific processing chambers are lined up and each process-specific processing chamber is all processed by a transfer device.

The processing chamber for each process consists of a preliminary firing chamber 20, a gas exchange chamber 22, a sealing section %, an annealing chamber 27, a rough drawing chamber A, a main drawing chamber 33, a sealing chamber A, a cooling chamber vane, and a take-out chamber 40. has been done.

Each processing chamber is arranged in a sealed device that is isolated from the outside.

Each processing chamber is equipped with a transfer device such as a cylinder feeder, a metal belt, a chain, etc. to move the trays.

A shutter is provided between the processing chambers for each step so that the processing conditions for each step do not affect other processing chambers.

The assembly and sealing jig is placed on a tray, and the tray is moved through each processing chamber by a transfer device to be processed.

The continuous integrated production apparatus of the present invention will be explained in detail below in order of each process.

The tray on which the assembly and sealing jig is placed first enters the pre-baking chamber 20 by a transfer device. A heating device (heater) is installed in this pre-baking chamber 20 to heat the chamber to 200 to 300°C.
It is held in What is the atmosphere inside the room?

The atmosphere may be used, but an oxidizing gas may be introduced to improve efficiency. Since the pre-firing chamber 20 is configured as described above, it is set in the assembly sealing jig and the remaining organic matter in the skin oxide solder is sufficiently oxidized when it is covered with the sealing part of the envelope. Heat to evaporation temperature.

When the pre-baking process is completed, the shutter 21 is opened and the tray enters the gas exchange chamber by the transfer device.

This gas exchange chamber 22 has a shutter 21.2 that can be sealed.
4 is disposed and is connected to a rotary pump 23 via a valve. It is also configured to be piped from an inert gas source 26 so that inert gas can be supplied thereto.

When the tray finally enters the room, the shutter 21 is closed and the gas in the room is exhausted by the rotary pump 23VC. Then, an inert gas (nitrogen gas, argon gas, carbon dioxide gas) is introduced to replace the inside of the display tube envelope with the inert gas.

Next, the shutter 24 opens and the tray moves to the sealing section 25.

The sealing part 25 is sealed in an inert gas atmosphere or a vacuum atmosphere.
It is heated to 00 to 600℃ to melt the oxide solder on the sealing surface, and is pressed from above and below by a jig.
Finally, the anode substrate and front container are sealed. Since the sealing furnace 25 is supplied with atmospheric gas from the atmospheric gas source 26, chemical changes in the cathode and the phosphor are prevented.

Since the sealed envelope 15 is placed on a tray together with the sealing jig, it is transferred to a slow cooling furnace n in the same inert gas atmosphere, where it is slowly cooled to about 200 to 400°C, and the oxide solder is removed. Fix from a molten state.

The slow cooling box envelope 15 is moved along with the tray to the next roughing chamber 28 by the transfer device by opening the shutter 29.30t. The shutter 9 here is a heat shield shutter, and the shutter 30 is a vacuum shutter.

When the tray of the sealing jig enters the roughing chamber 28, the vacuum shutter 30 is closed, the rotary pump 31 is activated, and the inside of the roughing chamber 28 is brought to a low vacuum state 5, for example, the degree of vacuum is 10-2 to 1O.
Exhaust until -3 Torr. When a predetermined degree of vacuum is achieved, the vacuum shutter 32 is opened and the tray of the sealing jig enters the water drawing chamber 33. Mizuhiki room 33.

Since the vacuum level is preliminarily reduced to about klOTorr, when the shutter 32 opens and enters the water drawing chamber, the vacuum level is 1O-5 Torr.
It's a little lower than r, but with the shutter 32K closed and Duhege explosion bomb 36YK: 1O-5Tor activated.
It is possible to evacuate in a short time to a high vacuum state of about r.

Next, the main draw chamber blade and the shutter 35 of the sealing chamber 34 are opened, and the tray of the sealing jig is moved to the sealing chamber. The shutter closes and the vacuum pump 36 operates, and while evacuating the sealing chamber until the vacuum level reaches t-1O-5 Torr, the filament-shaped cathode 14 of the fluorescent display tube is energized and the filament-shaped cathode 14 is energized. After completing the activation process of the cathode 14, the lid member 1
Part 1 is heated for t-g to adhere it to the lid member 11.
The oxide solder 16 is completely melted and the anode substrate IK is adhesively sealed.

The fluorescent display tube, whose envelope is sealed and maintained in a high vacuum state, is then slowly cooled by opening the shutter 37 and entering the cooling chamber. In this case, exhaust gas from the pre-firing chamber 20 and the gas replacement chamber 22 can also be used. The gradually cooled fluorescent display tube opens the shutter 39 and enters the take-out chamber 40, where it is further cooled and leaked to return the degree of vacuum to atmospheric pressure, and then taken out. In addition, slow cooling with heated air in the take-out chamber 40 and cooling chamber 38 is the 9th step to prevent the glass envelope from being rapidly cooled and thermally strained and cracked by rapidly introducing cold air. .

Does the fluorescent display tube taken out of the extraction chamber go through the gettering process and aging process, similar to the conventional display tube manufacturing method? It will be completed after a while.

In addition, the rough drawing chamber 28 and the water drawing chamber 33 are required to reach the vacuum level of 10-5 Torr required for the sealing process. −The rooms were set up by a friend,
By further increasing the number of roughing chambers 28, it is also possible to adjust the travel time of trays within the integrated device.

However, in the case of a front-emission type in which observation is made from the substrate side through the entire anode substrate 1, the anode substrate 1 is transparent, and the exhaust hole 5 is bored in the front plate 7.

Furthermore, in the case of display tubes such as FDPs and gas discharge tubes,
A specific atmospheric gas must be introduced into the display tube, and this process is carried out by supplying atmospheric gas from the atmospheric gas 41 and introducing it into the sealing chamber after creating a high vacuum in the sealing chamber 34. In addition to fluorescent display tubes, it is also possible to manufacture FDPs, gas discharge tubes, etc. by introducing atmospheric gas into the container 15 and then performing a sealing process.

According to the above, at least one of the anode substrate and the container part constituting the envelope is fully coated with oxide solder, and the electrode and the container part are placed on the anode substrate, and the oxide solder is fully coated facing the exhaust hole. The nine steps of placing the attached lid member, sealing, and sealing are performed continuously, and each step is transferred by a transfer device, resulting in continuous integrated production. It has the following features and effects.

(1) Although the processing conditions differ for each process, we created a system in which a processing chamber is set up for each process, and each processing chamber is moved using a transfer device, making it possible to have an in-line integrated production system, which allows for Productivity has increased and mass production of chipless display tubes has become easier.

(2) Since all display tubes are manufactured under the same processing conditions such as temperature conditions, ambient air conditions, and X sudden changes, uniform products of excellent quality can be produced at a high yield.

(3) There is no need to heat once and cool every 7' time as in the batch method, and the pre-firing chamber and sealing chamber are always kept heated, resulting in excellent thermal efficiency and energy savings.

(4) In addition, inert gas can be saved since it is only necessary to supply inert gas to the area where it naturally flows out.

(5) In order to create a high vacuum inside the display tube envelope, the vacuum system is made up of two or more chambers, a rough vacuum chamber and a main vacuum chamber, which shortens the time required to achieve high vacuum. This reduces manufacturing time and improves productivity.

(6) Since each processing step is manufactured in a device that uses outside air, it is processed continuously in a dust-free state, which improves quality.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a T-chipless fluorescent display tube manufactured by the manufacturing method of the present invention, Figure 2 is an explanatory diagram of a continuous integrated production device used in the manufacturing method of the present invention, and Figure 3 is a cross-sectional view of a chipless fluorescent display tube manufactured by the manufacturing method of the present invention. Flowchart showing the manufacturing method of the invention. FIG. 4 is a sectional view of a main part of an envelope of a conventional chipless fluorescent display tube.

Claims (1)

[Claims] An anode in which a phosphor layer is disposed on an anode conductor, an anode substrate in which an electrode such as a cathode is disposed facing the anode, and the anode substrate is sealed with an oxide solder on the periphery of the anode substrate, covering the former electrode, etc. An airtight envelope is constructed by the container part, and an exhaust hole is provided in a part of this airtight envelope, and this exhaust hole is sealed with a lid member, so that the inside of the envelope is kept in a vacuum atmosphere or in a specific environment. A method for manufacturing a display tube formed in an atmosphere includes a step of pre-baking the oxide solder adhered to at least one of the sealing portion of the anode substrate and the container portion, and replacing the inside and outside of the envelope with an inert gas atmosphere. a step of heating and sealing the anode substrate and the container part in an inert gas atmosphere, a step of slowly cooling the sealed envelope, and a step of forming a low vacuum atmosphere inside the envelope. A rough drawing process, a main drawing process in which a high vacuum atmosphere is created inside the envelope, a process in which the exhaust hole is closed and sealed by heating the lid member in a high vacuum atmosphere or a specific gas atmosphere, and a sealing process. It has a step of cooling the display tube that has been removed, and a take-out step of leaking the vacuum state of the take-out chamber, and has a processing chamber for each step, and the processing chambers for each step are connected via a shutter mechanism. A method of manufacturing a display tube is characterized in that the envelope is transferred to processing chambers for each process by a transfer device and processed continuously, resulting in integrated production.