KR20040101631A - Field Emitting Display - Google Patents

Abstract

PURPOSE: A field emission display is provided to place a getter ring containing a getter material inside a panel and activate the getter material after tip-off to form a getter layer in a wide area at the side of a frame, thereby maximizing gas absorption ability to continuously maintain high-degree vacuum state inside the panel. CONSTITUTION: A field emission display includes an upper substrate(110) having a fluorescent layer(112) and an anode electrode layer for applying voltage to the fluorescent layer, a lower substrate(120) on which a field emission emitter(124) is formed, and a frame(108) for maintaining a predetermined distance between the upper and lower substrates. A shadow mask(131) having electron beam passage holes is located at the side of the fluorescent layer. The shadow mask is welded to a rail(123) mounted on the upper substrate. A getter ring(105) filled with a getter material(103) is fixed to the side of the rail using an antenna.

Description

Field Emitting Display

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission display (FED), in particular using a shadow mask to solve a problem caused by secondary electrons generated after an electron beam emitted from an emitter impinges on a phosphor or other structure. In addition, the present invention relates to a field emission display device that allows a getter to be installed and activated to continuously maintain a degree of vacuum inside the display device.

1 is a schematic perspective view showing the structure of a conventional field emission display, FIG. 2 is a schematic cross-sectional view showing the structure of a conventional field emission display, and FIG. 3 is an enlarged cross-sectional view of part “A” of FIG.

As shown in the drawing, the conventional field emission display device has stripe-shaped red (12R), green (12G), and blue (12B) phosphors formed on an inner surface of the upper substrate 10. An anode electrode layer 11, which is a transparent electrode, is formed between the upper substrate 10 and the tricolor phosphors 12R, 12G, and 12B to apply an anode voltage.

In some cases, the anode electrode layer 11 may be replaced by applying an aluminum metal layer on the tricolor phosphors 12R, 12G, and 12B.

In addition, an emitter 24 for emitting an electron beam by field emission is formed on the lower substrate 20 on which the electron emission unit is formed.

Here, when the field emission is roughly described, when the applied voltage is about 109 [V / m] on the surface of the metal or semiconductor, the electron passes through the potential barrier due to the tunneling effect and the electron is released even under vacuum even at room temperature. Refers to the phenomenon.

Each emitter 24 is formed on the lower substrate 20 in the form of an XY matrix array so as to correspond to the red, green, and blue phosphors 12R, 12G, and 12B, respectively, for a full color display. The cathode electrode layer 22 and the gate electrode layer 28 are formed in a matrix form.

At this time, the emitter 24 to be used has been invented in various types so far, and even now, has been studied in various places for the improvement of efficiency and reliability.

Since the field emission in the conventional field emission display device as described above increases with the high vacuum, its emission efficiency increases, so that the degree of vacuum between the upper substrate 10 and the lower substrate 20 should be maintained at 10 ^-6 torr or less. The height of a certain space must be secured for the electron to accelerate.

To this end, in the prior art, the spacer 29 is inserted into the panel to secure a space, and the edge of the panel is sealed using the frame 8 and the frit glass 21, and the inside of the panel is opened through the exhaust pipe 2. After sufficiently exhausting the gas, a vacuum was secured inside by using a tip-off method.

However, when the spacer 29 is used inside such a panel, various problems appear. First, the spacer 29 must be located within the width of the black matrix 13 between the phosphor and the phosphor in order not to cover the image. Since the width is narrow as many as several tens of microns, the predetermined width may be small. Not only is it difficult to manufacture the spacer 29 having a height, but also it is very difficult to align and mount the black matrix 29 so that the manufacturing yield of the device is significantly reduced.

Secondly, as mentioned above, the current state of the art is difficult to manufacture the spacers 29 having a certain height and strength, so that the height of the spacer 29 thus far has a height of about 1 mm.

Therefore, it is very difficult to maintain a gap between the upper substrate 10 and the lower substrate 20 by 1 mm or more, and in such a small gap, it is difficult to form and maintain a high vacuum, and the upper anode electrode layer 11 Because it is impossible to apply a high voltage of several kV), it is impossible to realize a high-quality image such as a cathode ray tube (CRT), and the lifetime of the device is shortened because the phosphor efficiency is low.

Third, the electron beam 1 emitted from the emitter 24 collides with the spacer 29 itself, and the shadow of the spacer 29 is reflected on the image due to the generation of secondary electrons, or the spacer 29 is charged ( charging) causes electrical problems such as discharging and causes destruction of the device.

In particular, one of the major problems of the conventional field emission display device is the generation of secondary electrons generated when the electron beam 1 collides with the phosphor 12 or an aluminum layer to which high pressure is applied.

This is because when the electron beam 1 accelerated by the high voltage collides with the phosphor 12 or the aluminum layer, a large number of secondary electrons with high energy are generated, which secondary electrons are reflected or scattered. It collides with phosphors of other colors nearby, causing undesired light emission, which lowers the color purity of the display device, and reflects and collides with the emitter 24, causing damage to the surface of the emitter 24, thereby reducing electron emission. Problem occurs, or the device is destroyed.

In order to solve this problem, to maintain the gap between the upper substrate 10 and the lower substrate 20 without using the spacer 29 in the panel, and to prevent problems caused by secondary electrons A technique has been proposed in which a shadow mask 31 is provided at a lower portion of the phosphor 12 layer to absorb or block when secondary electrons generated are reflected off.

FIG. 4 is a schematic cross-sectional view showing the configuration of a conventional field emission display device equipped with a shadow mask, and FIG. 5 is an enlarged cross-sectional view of portion “B” of FIG. 4, showing a conventional field emission display device as shown in FIG. The key is not to use a spacer inside the panel, instead of forming a thick thickness of the upper substrate 10, lower substrate 20, and the frame 8, the upper substrate 10 in spite of the high vacuum pressure inside the panel ) And the lower substrate to stably maintain a predetermined height.

In the conventional field emission display, a shadow mask 31 is provided under the phosphor 12 layer to solve the problem of secondary electrons generated when the electron beam 1 collides with the phosphor 12 or the aluminum layer.

To this end, in the prior art, a metal structure having a predetermined height, called a rail 23, is filled around the effective screen inside the panel, and the frit glass 21R is filled therein, and then placed on the inner surface of the upper substrate 10, and in an electric furnace or the like. By heating to 400 ° C. or more and sintering, bonding was performed with very strong strength, and then a method of pulling / welding the shadow mask 31 on the rail 23 was used.

The upper substrate 10 to which the phosphor 12, the rail 23, the shadow mask 31, the anode electrode 11, and the like are attached, the emitter 24, the cathode electrode 22, and the gate electrode 28 After the frit glass 21F is coated on both sides between the lower substrates 20 formed thereon, the frame 8 having the rectangular shape is positioned, and the alignments formed on the upper substrate 10 and the lower substrate 20, respectively. After aligning the two substrates using the mark, and heating and sintering in an electric furnace or the like, after sufficiently exhausting the gas inside the panel through the exhaust pipe (2), the inside using the tip-off method Vacuum was ensured.

In this case, a getter 3 is mounted inside the exhaust pipe 2, and the getter 3 material is activated through an activation process after the tip off is completed, thereby absorbing gas in the panel. It is possible to maintain the degree of vacuum inside.

However, the getter (3) is sealed in the exhaust pipe (2) of the field emission display device and then performs a function of adsorbing gas inside the panel through an activation process, which functions in a narrow area within the exhaust pipe (2). Therefore, as the probability of adsorbing the gas is lowered, the efficiency cannot be sufficiently exhibited.

That is, its absorption capacity is lower than the amount of outgassing generated during operation of the field emission display device, and the degree of vacuum inside the entire panel is lowered. Therefore, the efficiency of field emission, the luminous efficiency, and the lifetime of the device are reduced. There is a problem that causes problems.

The present invention has been proposed to solve the above problems, and an object of the present invention is to mount a getter ring containing a getter material inside the panel and to activate (spread) the getter material contained in the getter ring after the tip-off frame. It is an object of the present invention to provide a field emission display device in which a getter film is formed in a large area of the side surface, thereby maximizing gas absorption capability and continuously maintaining a high vacuum inside the panel.

1 is a schematic perspective view showing the configuration of a conventional field emission display.

2 is a schematic cross-sectional view showing the configuration of a conventional field emission display.

3 is an enlarged cross-sectional view of portion “A” of FIG. 2;

4 is a schematic cross-sectional view showing the configuration of a field emission display device equipped with a conventional shadow mask.

5 is an enlarged cross-sectional view of the portion “B” of FIG. 4.

6 is a schematic cross-sectional view showing the configuration of a field emission display device according to the present invention;

7 is a front view of a getter assembly applied to the present invention.

8 is a graph showing the results of experiments measuring the degree of vacuum change inside the panel according to the process of the present invention.

9 is a front view of a getter assembly according to an embodiment of the present invention.

Figure 10 is an illustration of mounting the getter assembly according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

1,101: electron beam 2,102: exhaust pipe

3,103: getter 4,104: antenna

5,105: gettering 6,106: exhaust hole

8,108: frame 10,110: upper substrate

11: anode electrode layer 12, 112 phosphor

13: black matrix 20,120: lower substrate

21: frit glass 22: cathode electrode layer

23,123: Rail 24,124: Emitter

26: insulator layer 28: gate electrode layer

29: spacer 31,131: shadow mask

According to an aspect of the present invention, there is provided a field emission display device comprising: an upper substrate including a phosphor layer and an anode electrode layer for applying a voltage to the phosphor layer; A lower substrate on which a field emission emitter for emitting electrons is formed; In the field emission display device for evacuating the inside of the panel consisting of a frame for maintaining a predetermined interval between the upper substrate and the lower substrate by using an exhaust pipe,

A shadow mask having a through hole for passing electron beams is provided on the fluorescent surface side, and the shadow mask is welded on a rail installed on an upper substrate, and a getter ring filled with getter material on the side of the rail is fixed by an antenna. It is characterized by that.

Here, the gettering is fixed to face the inner wall of the frame.

Here, the gettering is characterized in that formed in the horizontal shape.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

6 is a schematic cross-sectional view showing the configuration of a field emission display device according to the present invention.

As shown in the figure, in the field emission display device according to the present invention, the emitter 124 is formed in a matrix form on the lower substrate 120, and the phosphor 112 is formed in the matrix form on the upper substrate 110. In addition, the upper substrate 110 is provided with a rail 123.

In addition, a shadow mask 131 is welded and installed on the front surface of the rail 123 to prevent display element quality deterioration and destruction due to secondary electron scattering, and a getter ring 105 is provided on one side of the rail 123. ) Is installed by welding.

Here, the getter ring 105 is filled with a getter 103 material therein, and is connected to a metal antenna 104 extending a predetermined length, the other end of the antenna 104 is the side of the rail 112 Due to the welding, the getter 103 filling surface is installed opposite the frame 108 side.

A frame 108 is formed to maintain an appropriate gap between the upper substrate 110 and the lower substrate 120.

At this time, the both ends of the frame 108 is sealed with frit glass so that the inside of the panel maintains a vacuum tightness.

After the upper substrate 110 and the lower substrate 120 are sealed by frit glass to maintain a constant gap and maintain the airtightness by the frame 108, the exhaust formed on the upper substrate 110 or lower substrate 120 side The gas inside the panel is exhausted through the exhaust pipe 102 connected to the hole 106.

At this time, the exhaust pipe 102 is heated by tip-off after securing a vacuum degree of about 10 ⁻⁶ torr or more through the exhaust process.

In the present invention, since the getter is not mounted in the exhaust pipe 102 unlike the prior art, the length of the exhaust pipe 102 remaining after the tip-off is shorter by 50% or more than in the prior art. Thus, the length of the exhaust pipe 102 is shortened. In this case, a subsequent process such as attaching a flexible printed circuit (FPC) is advantageous.

After the exhaust is completed as described above, the inside of the panel is maintained in a vacuum state, but the gas generated during the tip-off process, the gas introduced into the panel, the residual gas adsorbed by the various components inside the panel, and the display element and the operation Outgassing and the like that may occur still exist.

As shown in FIG. 6, when energy is applied to the getter 103 material inside the getter ring 105 installed toward the inner wall of the frame 108 by using a high frequency heating apparatus, the getter 103 material is formed. It is scattered to form a getter film on the inner wall of the frame 108, and the gas remaining in the panel is continuously adsorbed and removed by the getter film, thereby ultimately increasing the degree of vacuum inside the panel.

As shown in FIG. 7, a getter 103 material is contained in the getter ring 105, and the getter 103 material does not react with the gas in an inactive state until energy is scattered. When received and scattered, the getter film is deposited on the inner wall of the frame 108 to be activated to adsorb gas inside the panel.

The getter 103 material includes, for example, barium (Ba) or zirconium (Zr) as a main component, and the gettering 105 is a high melting point material that does not melt even in a high heat in which the getter 103 material is scattered. The antenna 104 serves to prevent such high heat from being transferred to the rail 123 or the shadow mask 131.

In addition, since the external energy for scattering the getter 103 is selectively applied to only the getter 103 by using a radio frequency or the like, it does not affect the internal parts of the panel such as the emitter 124.

In the present invention as described above, since the distribution area of the getter 103 film formed on the inner wall of the frame 108 can be widened, the gas adsorption efficiency is very high. Therefore, it is possible to continuously maintain the excellent vacuum degree inside the panel.

8 is a graph showing the results of experiments measuring the degree of vacuum change inside the panel according to the process of the present invention. As shown in the graph, in the tip off section, the vacuum degree is gradually dropped by the gas discharged from the exhaust pipe 102 and introduced into the panel, and the tip off ends, and the getter 103 is scattered and activated to rapidly increase the vacuum degree. It can be seen that the process time between tip off and getter activation is excluded from the city. After the getter 103 is activated, it can be seen that the high vacuum state is continuously maintained.

9 is a front view of the getter assembly according to one embodiment of the present invention, and FIG. 10 is an illustration of mounting the getter assembly according to one embodiment of the present invention.

As shown in the drawing, the getter assembly according to the exemplary embodiment of the present invention has a getter housing 205 having a horizontal shape to fill the getter 203 material, and the getter housing 205 is fixed to the inside of the panel. Antenna 204 to be configured.

In addition, since the field emission display device of the present invention is extremely thin, as shown in FIG. 10, the antenna 204 is diagonally welded between the rail 123 and the getter accommodating part 205, thereby making it thinner. Installation of the getter assembly inside the panel can be made more smoothly.

This, of course, applies equally to a getter assembly using a getter ring made in a circular shape.

The present invention as described above has the following effects.

First, the present invention is equipped with a getter ring containing the getter material in the inside of the panel, and after the tip off, the getter material contained in the getter ring is activated (spread) to form a getter film in a large area, thereby improving the absorption capacity of the gas It maximizes and maintains the high vacuum inside the panel continuously.

Secondly, the high vacuum degree inside the panel of the field emission display device is directly connected to the emission efficiency of electrons, thereby extending the life of the field emission display device and securing reliability.

Third, since the present invention does not mount the getter in the exhaust pipe, the length of the exhaust pipe remaining after the tip off is shortened by 50% or more as compared with the conventional method, and the subsequent process such as the attachment of a flexible printed circuit (FPC) is advantageous.

Claims (3)

An upper substrate provided with a phosphor layer and an anode electrode layer for applying a voltage to the phosphor layer; A lower substrate on which a field emission emitter for emitting electrons is formed; In the field emission display device for evacuating the inside of the panel consisting of a frame for maintaining a predetermined interval between the upper substrate and the lower substrate by using an exhaust pipe, A shadow mask having a through hole for passing electron beams is provided on the fluorescent surface side, and the shadow mask is welded on a rail installed on an upper substrate, and a getter ring filled with getter material on the side of the rail is fixed by an antenna. And a field emission display device. The method of claim 1, And the gettering is fixed to face the inner wall of the frame. The method of claim 1, And the gettering is formed horizontally.