KR100380231B1 - Structure and manufacturing method for a exhaust pipe of field emission display - Google Patents

Abstract

The exhaust pipe structure and the manufacturing method of the field emission device are published. The exhaust pipe structure of the field emission device according to the present invention comprises a lower frit glass applied on the upper substrate; A middle frame formed on the lower frit glass; A predetermined opening is formed at one side of the middle frame and inserted into the opening to form a parallel arrangement with the panel; Upper frit glass applied onto a middle frame into which an exhaust pipe is inserted; The lower substrate is bonded to the upper frit glass. The exhaust pipe manufacturing method of the field emission device according to the present invention comprises the steps of applying a lower frit glass on the upper substrate; Forming a middle frame on the lower frit glass; A predetermined opening is formed at one side of the middle frame, and a tube is inserted into the opening; Applying upper frit glass onto the middle frame into which the tube is inserted; Mounting a getter on the upper substrate; And bonding the upper substrate and the lower substrate to be bonded.

Therefore, since exhaust pipes are arranged in parallel on the panel, the exhaust efficiency is improved and the process time is reduced.

Description

STRUCTURE AND MANUFACTURING METHOD FOR A EXHAUST PIPE OF FIELD EMISSION DISPLAY}

The present invention relates to a field emission device, and more particularly, to an exhaust pipe structure and a manufacturing method of the field emission device in which the exhaust pipe is formed on the upper electrode, the exhaust pipe is arranged in parallel with the panel.

In general, the field emission device is a device that emits cold electrons due to the tunnel effect by applying a relatively low voltage, for example, a voltage of about 5 to 10V by using a phenomenon in which the electric field is concentrated on the sharp part of the emitter tip. The field emission device formed by using both the high definition of the cathode ray tube and the light and thin advantages of the liquid crystal display have attracted attention as a next generation display device.

In particular, the field emission device can not only manufacture a light and thin type, but also solve the problems of process yield, manufacturing cost, and enlargement, which are crucial disadvantages of the liquid crystal display.

The field emission device is basically formed by separating the upper electrode coated with a fluorescent material and the lower electrode provided with a cathode ray emitting device by a predetermined distance, and maintaining a space formed therebetween in a vacuum state, When a voltage of several kilovolts or hundreds of volts is applied between the lower electrodes, the cathode electrons are strongly emitted from the cathode ray emitting device provided in the lower electrode, thereby colliding with the fluorescent material applied on the upper electrode. It consists of cells that cause the material to emit light.

Hereinafter, a conventional field emission device will be described with reference to FIGS. 1 and 3.

First, as shown in FIG. 1, the insulating layer 120, the gate electrode 130, the emitter 140, and the like are formed on the substrate 100 on which the lower electrode 110 is formed. In addition, the phosphor 150 and the like are formed on the substrate 170 on which the upper electrode 160 is formed. The spacer 180 is supported so that the lower electrode 110 and the upper electrode 160 are spaced apart from each other by a predetermined distance.

In more detail, when sufficient voltage is applied to the lower electrode 110 and the gate electrode 130, a strong electric field is formed thereby. Then, the electrons are released into the vacuum by the quantum mechanical tunneling phenomenon in the emitter 140. In this case, a field emitter array (FEA) is matrix addressed through the gate electrode 130 and the lower electrode 110, and electrons are emitted during a time when a voltage is applied to the gate electrode 130.

Then, due to the strong voltage of the upper electrode 160, the electrons collide with the phosphor 150 formed on the upper electrode 160 with high energy to emit light.

The field emission array, which is an electron emission source in the field emission device, maintains a distance between the emitter 140 and the gate electrode 130 at a sub-micron level, and between the emitter 140 and the gate electrode 130. A high field of about 10 ⁷ V / cm is applied. At this time, if the very short distance of the submicron between the emitter 140 and the gate electrode 130 is not reliably maintained at high vacuum, discharge and vacuum dielectric breakdown may occur. In addition, if the vacuum inside the panel is not good, the neutral particles present in the panel collide with the emitting electrons to generate cations, which sputters to the tip and degrades the device. In addition, when the accelerating electrons collide with the residual neutral gas to lose energy and collide with the fluorescent film, the emission luminance may be lowered.

For this reason, maintaining the inside of the panel of the field emission device in a high vacuum is the most important task that influences the characteristics of the panel.

2 shows a schematic diagram of vacuum packaging a panel of a conventional field emission device using a vacuum pump in the air.

As shown in FIG. 2, the exhaust pipe 200 is erected by dispensing the first frit glass 200 on the lower electrode 110. In addition, the second frit glass 220 is dispensed to the periphery of the upper electrode 160 where the spacer 180 is formed, and then dried. The height of the second frit glass 220 dispensed to the upper electrode 160 is formed to be about 1 to 2 mm higher than the gap of the final panel to allow for 30 to 40% reduction during plastic sintering. In addition, the upper electrode 160 and the lower electrode 110 are aligned. Then, during main sintering, the gap of the final panel is formed by pressing and clamping the upper electrode 160 and the lower electrode 110. In other words, the panels prepared at the time of main sintering are transferred to a heating furnace and performed at about 400 to 450 ° C. higher than the sintering temperature.

At this time, when the main sintering is performed in a high temperature oxygen atmosphere, devices such as the lower electrode, the insulating layer, the gate electrode, and the emitter of the field emission device react with oxygen, carbon, etc. in the air, and the light emission characteristics are weakened. Accordingly, in order to improve the light emitting characteristics of the field emission device, an inert gas 230 is flowed into the panel and the entire furnace to prevent the devices from reacting with oxygen even during a high temperature process.

3 is a diagram illustrating an embodiment of performing a vacuum packaging process of a panel equipped with an exhaust pipe.

As shown in Figure 3, the panel is provided with a vacuum pump (300). The panel is pumped and heated to remove impurities inside the panel. The panel is heated by the heating device 310, and when the panel reaches the appropriate degree of vacuum, the middle of the exhaust pipe 210 is heated and melted by the local heating device 320 (pinch off process). The panel is isolated from the chamber to complete an independent panel.

However, since the degree of vacuum of the isolated panel decreases during the pinch-off process, the getter 330 pre-mounted inside the panel is activated at a high temperature to recover the degree of vacuum and complete the final panel.

However, this vacuum packaging process has some problems.

First, since the panel is exposed to high temperature during the main sintering, the injection of an ignit gas also causes deterioration of characteristics due to oxidation of the emitter by oxygen and reaction with other gases. In addition, there is a risk that the element of the lower electrode is contaminated by the organic binder included in the frit glass through the process of attaching the tube to the rear electrode using the frit glass. Damage to the emitter element directly affects the lifetime of the panel, which is one of the most critical problems in the field emission device.

Second, since the exhaust pipe is installed at right angles to the direction of the panel, the exhaust efficiency through the pump is reduced. In this case, the exhaust time is long, so that the process time is long. Therefore, the field emission device has one disadvantage that is for commercial purposes.

Third, the installation at a right angle of the exhaust pipe becomes a factor of thickening of the panel. Increasing the thickness of the panel is a problem that is disposed with the flow of the display industry that is oriented toward thin displays.

The present invention has been made in an effort to provide an exhaust pipe structure and a manufacturing method of a field emission device for arranging the exhaust pipes in parallel so that the flow of gas in the exhaust pipe is parallel to the exhaust pipes in order to effectively solve the problems of the prior art. have.

1 is a view showing the internal cross-sectional structure of a conventional field emission device.

2 shows a schematic diagram of vacuum packaging a panel of a conventional field emission device using a vacuum pump in the air.

3 is a diagram illustrating an embodiment of performing a vacuum packaging process of a panel equipped with an exhaust pipe.

4 to 10 is a view showing an embodiment of a method of manufacturing a field emission device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

400: upper substrate 410: upper electrode

420: middle frame 700: exhaust pipe

430: upper fritted glass 440: pressing plate

900: getter

One surface of the present invention for achieving the above technical problem is a lower frit glass applied on the upper substrate; A middle frame formed on the lower frit glass; A predetermined opening is formed at one side of the middle frame and inserted into the opening to form a parallel arrangement with the panel; Upper frit glass applied to the middle frame into which the exhaust pipe is inserted; And a lower substrate bonded to the upper frit glass. Another aspect of the invention the step of applying a lower frit glass on the upper substrate; Forming a middle frame on the lower frit glass; A predetermined opening is formed at one side of the middle frame, and a tube is inserted into the opening; Applying upper frit glass onto the middle frame into which the tube is inserted; Mounting a getter on the upper substrate; And bonding the upper substrate and the lower substrate to be bonded to each other.

Hereinafter, an exhaust pipe structure and a method of forming the field emission device of the present invention will be described with reference to FIGS. 4 to 10.

As shown in FIG. 4, after the phosphor is coated on the upper substrate 400 and a phosphor process such as a metal back, a frit glass 410 is applied.

In this case, it is difficult to maintain the gap between the upper substrate 400 and the lower substrate (not shown) by more than 1 mm using only the frit glass 410. However, since the interval between the upper substrate 400 and the lower substrate (not shown) must be maintained at least 1 mm to enable high voltage, as shown in FIG. 5, the upper substrate 400 and the lower substrate (not shown). The use of a middle frame 420 made of glass material is effective to maintain the gap between the upper substrate 400 and the lower substrate (not shown).

Therefore, the frit glass 410 applied on the upper substrate 400, that is, the frit glass 410 applied under the middle frame 420 is called a lower frit glass, and the middle frame ( The frit glass applied onto the 420 is referred to as upper frit glass.

Meanwhile, a lower frit glass 410 is coated on the upper electrode 400. In this case, the thickness of the lower frit glass 410 is preferably about 600 ~ 800㎛, it is preferable to apply the lower frit glass 410 in two divided. In other words, the lower frit glass 410 is first applied and dried to have a height of about 300 to 400 μm. Then, the secondary lower frit glass 410 is applied to form a height of about 600 ~ 800㎛. At this time, when the secondary lower frit glass 410 maintains viscosity, the middle frame 420 is mounted and dried. In this case, the height to the middle frame 420 is formed 200 ~ 300㎛ lower than the target height.

The reason for applying the lower frit glass 410 in two portions is as follows.

Conventionally, a middle frame 420 is formed on the lower frit glass 410 in a state where the lower frit glass 410 is viscous and dried. Then, the binder or air in the lower frit glass 410 is pressed out by the middle frame 420, a problem occurs that the void (void) is generated on the upper electrode surface.

Therefore, in order to solve the problem, the void problem can be solved by performing the first coating and drying process of the lower frit glass, followed by the second frit glass coating and frame mounting.

As illustrated in FIGS. 5A and 5B, an opening through which a predetermined exhaust pipe may be inserted is formed at one side of the middle frame 420. In this case, the opening is formed to be about 10% wider than the diameter of the exhaust pipe (not shown) to be inserted. In this case, using the water jet method, the opening may be easily formed without the middle frame 420 being thermally impacted.

Referring to FIG. 6, an appropriate amount of frit glass 600 is applied to the bottom of the opening formed in the middle frame 420 so that the exhaust pipe is attached to the opening well.

As shown in FIGS. 7A and 7B, the exhaust pipe 700 is inserted into the opening while the viscosity of the lower frit glass 600 applied in the opening remains, and then the frit glass 600 is inserted into the opening 120. When the drying process is performed at a temperature of about 5 minutes for about 5 minutes, the exhaust pipe 700 is dropped or distorted. In this case, when the exhaust pipe 700 is disposed in parallel with the panel, the gas flowing inside the panel can easily escape to the exhaust pipe 700, thereby improving the exhaust efficiency.

In addition, the exhaust pipe 700 is disposed in parallel on the middle frame 420, and then a first sintering process is performed. The first sintering process is performed until the middle frame 420 is completely sintered. When the primary sintering process is completed, the height of the lower frit glass 410 is reduced by about 30 to 40%. In this case, the height of the frit glass formed on the upper electrode 400 is a value obtained by adding the height of the middle frame 420 to the height of the reduced lower frit glass 410. At this time, the height to the middle frame 420 formed on the upper substrate 400, the primary sintering process is completed is preferably maintained at a height minus 200 ~ 300㎛ from the interval of the desired panel.

As shown in FIG. 8, the upper frit glass 430 is coated on the middle frame 420, and a sintering process is performed. The presintering process depends on the burnout conditions of the binder used, but usually takes about 1 hour at around 300 ° C. The height of the upper frit glass 430 after this process is reduced by about 20 to 30%. Therefore, the upper frit glass 430 should be applied with the reduction in the height of the upper frit glass 430 in mind. In this case, the height of the upper frit glass 430 is preferably about 400 ~ 500㎛.

As shown in FIGS. 9A and 9B, when the pre-sintering process of the upper frit glass 430 is completed, a getter 900 is mounted on the upper electrode 400. In this case, since the getter 900 may be damaged by a high temperature in the sealing process, it uses ST122 or ST121 provided by SAES, which is not easily damaged even at a temperature of 300 to 400 ° C.

When the mounting of the getter 900 is completed, the lower substrate 440 is aligned, bonded, and then the final sealing process is performed.

The final sealing process is to follow the surface of the upper frit glass 430 locally using a laser (not shown) to complete the sealing process. The laser sealing process is possible at temperatures significantly lower than conventional sealing temperatures. Therefore, a large part of the pollutants are blocked.

As shown in FIG. 10, after the laser sealing process is completed, the panel is evacuated and heated. Then, a tip-off process of the exhaust pipe 700 is performed. In this case, since the outer diameter of the exhaust pipe 700 is 2 to 3 times smaller than the conventional structure of the heater (heater) may be slightly different, there is no major difference from the tip off process.

Then, a high temperature activation process of the getter 900 is performed using a laser. Energy transfer to the local getter 900 using a laser can effectively activate the getter 900 inside the panel without a separate process. In this case, the getter 900 does not need to install a separate getter room.

Therefore, it is possible to form the exhaust pipes 700 arranged in parallel at the close position of the panel.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the appended claims technical spirit.

The exhaust pipe structure as described above has various effects.

First, since it is disposed in parallel with the panel, the exhaust efficiency is superior to that of the vertical exhaust pipe, thereby reducing the processing time.

Secondly, a thin display is realized by the structure arranged in parallel with the panel.

Third, since the exhaust pipe is formed during the manufacturing process of the upper substrate, the upper electrode is not affected by the frit process. Thus, oxidation or damage of the emitter is significantly reduced, and the life of the panel is improved.

Fourth, the getter is formed inside the panel, whereby the internal vacuum is effectively maintained.

Claims (4)

A lower frit glass applied onto the upper substrate; A middle frame formed on the lower frit glass; A predetermined opening is formed at one side of the middle frame and inserted into the opening to form a parallel arrangement with the panel; Upper frit glass applied to the middle frame into which the exhaust pipe is inserted; An exhaust pipe structure of a field emission device comprising a lower substrate bonded to the upper frit glass. The method of claim 1, And the method of manufacturing the middle frame is a jet jet method. The method of claim 1, An exhaust pipe structure of a field emission device, characterized in that the lower frit glass is applied twice. Applying a lower frit glass on the upper substrate; Forming a middle frame on the lower frit glass; A predetermined opening is formed at one side of the middle frame, and a tube is inserted into the opening; Applying upper frit glass onto the middle frame into which the tube is inserted; Mounting a getter on the upper substrate; And an upper substrate and a lower substrate bonded to each other to seal the upper substrate and the lower substrate.