KR100275315B1 - Insulator composition for field emission device - Google Patents

Abstract

PURPOSE: An insulator composite for field emission display is provided to ward barrier rib in cell and forming a visible ray cut off member at sustain electrode. CONSTITUTION: A pair of a sustain electrode is composed of a transparent electrode to make a surface discharge being formed parallel to an upper substrate(24) and a bus electrode to minimize a resist of the transparent electrode. A barrier rib is formed to secure a cell space at a lower substrate(22). An address electrode is formed at the middle height of the barrier rib and makes an address discharge. A first dielectric layer is formed on the pair of the sustain electrode. A protection film is formed on the first dielectric layer. A second dielectric layer is formed on the address electrode and protects the address electrode from the discharge. A phosphor is sprayed on the barrier rib and the lower substrate(22).

Description

Composition of Insulator for Field Emission Element

The present invention relates to a field emission device, and more particularly to an insulator composition for a field emission device. The present invention also relates to a field emission device using the insulator composition.

In general, a field emission display (hereinafter referred to as "FED") includes a row driver for supplying a driving voltage, a column driver for supplying image data, the row and column A pixel formed in a matrix structure is provided at the intersection of the driver. In the FED, electrons are emitted from pixels formed in a matrix structure according to a driving voltage or image data supplied from a raw driver or a column driver to display an image. At this time, each pixel Pixel has a sub-pixel of red (hereinafter referred to as "R"), green (hereinafter referred to as "G"), and blue (hereinafter referred to as "B"). Quantum mechanical tunnel effect by concentrating a high electric field between a cathode electrode formed on each of R, G, and B of the pixel and an anode electrode formed on the pixel. By means of emitting electrons. The emitted electrons are accelerated by the gate voltage and collide with the phosphor film formed under the anode electrode to excite the phosphor. The light is emitted to display an image. On the other hand, in the case of the micro tip method, which is one of FED's methods, the spindt type using a thin film and an etching process is the mainstream of the method of manufacturing the micro tip. In addition to the complexity of the process, there is a significant problem in considering performance and mass productivity because of the use of low voltage phosphors. Due to this, a study on a planar FED using a high voltage phosphor and a planar electron source method and a printable field emission (PFE) method, which are easier to manufacture than a micro tip method, has been conducted. It is actively underway. Hereinafter, the PFE, which is one of the planar FEDs, will be described. PFE is a field emission device that employs a printable emitter formed by coating and firing a paste containing conductive particles on an electrode material on a glass substrate.

Referring to FIG. 1, the PFE is formed on the glass substrate 2 and has a conductive conductive layer 4, an insulating layer 6 formed on the conductive layer 4, and the insulating layer 6. And conductive particles 8 which are distributed inside of and emit electrons. When a predetermined voltage is applied to the conductive layer 4 and the electrode (not shown) positioned above the insulating layer 6, electrons are emitted from the conductive layer 4 toward the conductive particles 8 and the conductive particles 8 are provided. The electrons transferred to the vacuum are emitted through the sharp end of the conductive particles 8. This will be described in detail with reference to FIGS. 2A and 2B. As shown in FIG. 2A, an electric field is applied to the insulating layer 6 formed on the conductive layer 4 and the conductive particles 8 inside the insulating layer 6 by the voltage applied to the conductive layer 4. Electric Field) is formed. As shown in FIG. 2B, an area in which an electric line of force is concentrated appears between the conductive layer 4 and the conductive particles 8. In addition, a breakdown occurs in a region where the electric line of force is concentrated, and a conducting channel is formed between the electrically isolated conductive layer 4 and the conductive particles 8. As a result, electrons in the conductive layer 4 are released to the conductive particles 8 through the conductive channel. On the other hand, due to the electrons emitted to the conductive particles 8, an electric field is formed on the opposite side of the conductive layer 4 (that is, the upper portion of the conductive particles) to distribute the electric field lines. At this time, at the sharp end of the conductive particles 8, a conductive channel is formed between the conductive particles 8 and an electrode (not shown) formed on the insulating layer 6 to emit electrons in a vacuum. At this time, the electrons emitted by the vacuum collide with the phosphor film to excite and emit the phosphor to display an image. In addition, the insulating layer 6 is coated and baked to a predetermined thickness by a paste including conductive particles on the conductive layer 4 by spin coating, screen printing, or the like. To form. In addition, the PFE includes an insulating layer 6 formed on the conductive layer 4, conductive particles 8 distributed in the insulating layer 6, and a vacuum region formed on the insulating layer 6. It is formed to have a "MIMIV (Metal-Insulator-Metal-Insulator-Vacuum)" structure (hereinafter referred to as "MIMIV").

However, since the paste is resin-based, the paste deteriorates due to the heat generated during the operation of the PFE and the temperature of 400-450 ° C. which is heated in the sealing process of joining the upper and lower glass substrates together. Problem is being derived. As a result, there is a demand for a glass-based paste capable of minimizing the influence of heat.

Accordingly, an object of the present invention is to provide an insulator composition and a manufacturing method for a field emission device that satisfies thermal requirements.

Another object of the present invention is to provide a field emission device using an insulator composition.

1 is a view showing the structure of a printable field emission device.

2A and 2B illustrate the electron emission process of FIG. 1.

3 is a view showing an insulator manufacturing process procedure of the field emission device according to the first embodiment of the present invention.

4 is a view showing an insulator manufacturing process procedure of the field emission device according to the second embodiment of the present invention.

5 is a view showing a field emission device according to the present invention.

<Description of the code | symbol about the principal part of drawing>

2,12 glass substrate 4,14 conductive layer

6,16: insulating layer 8,18: conductive particles

In order to achieve the above object, the insulator composition according to the present invention contains SiO ₂ -ZnO-based glass.

In addition, the field emission device using the insulator composition according to the present invention includes an insulating layer in which SiO ₂ -ZnO-based glass is formed to a predetermined thickness.

In addition, the method for manufacturing an insulator according to the present invention comprises the steps of forming an amorphous glass powder, mixing conductive particles and an organic solvent in the powder at a predetermined ratio to form a paste, and pasting the paste on a substrate on which the conductive layer is formed. Forming an insulating layer by applying a thickness; and sintering the substrate at a predetermined temperature for a predetermined time.

Other objects and features of the present invention other than the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

The manufacturing method of the field-emitting device insulator will be described. After the raw material of amorphous glass is mixed and melted in a constant composition ratio to form a powder having fine particles by rapid cooling, the conductive particles and Organic solvent (Vehicle) is mixed in a predetermined ratio to make a paste (Paste). The paste including the conductive particles is applied to a glass substrate on which the conductive layer is formed to have a predetermined thickness and sintered at a constant temperature to form an insulator. The insulator manufactured in this way has improved thermal requirements.

Hereinafter, the composition ratio of the insulator according to the present invention and an embodiment of the method of manufacturing the same will be described, but the scope of the present invention is not limited to these embodiments.

First embodiment

In the first embodiment of the present invention, the composition of the insulator and the manufacturing method thereof will be described. The insulator will have a composition of SiO ₂ -ZnO based amorphous glass powder. At this time, the composition ratio of the SiO ₂ -ZnO-based amorphous glass powder is shown in Table 1.

The composition ratio of Table 1 is the calculated to the weight of SiO ₂ -ZnO-based glass powder, amorphous glass is 100% by weight.

Composition ratio of SiO ₂ -ZnO based amorphous glass powder Amorphous glass weight % ZnO 20-40 SiO ₂ 15-23 B ₂ O ₃ 10-20 Na ₂ O 3-8 K ₂ O 2-10 CaO 1-5 Al ₂ O ₃ 1-4 PbO 0-25 Li ₂ O 0-5 Sb ₂ O ₃ 0-4 As ₂ O ₃ 0-2

The SiO ₂ -ZnO-based glass has a low firing temperature when sintered to a low PbO content glass having a low PbO content.

Referring to FIG. 3, there is shown a diagram illustrating an insulator manufacturing process of a printable field emission device according to a first embodiment of the present invention.

Forming Powder of SiO ₂ -ZnO Amorphous Glass (Step 21) The powder forming process of the SiO ₂ -ZnO amorphous glass will be described in detail. In the first step, raw materials of SiO ₂ -ZnO amorphous glass are used. Material) is mixed according to the composition ratio of Table 1. Raw material of the SiO ₂ -ZnO-based amorphous glass is weighed according to a predetermined composition ratio and mixed in a tumbling mixer for a predetermined time (for example, 10 hours). The raw materials mixed in the second process are put into a melting furnace and melted. Melting condition is melted for a predetermined time (for example, 1-5 hours) at 1000-1200 ℃, and homogenized by stirring 2-3 times so that raw materials are melted evenly during melting. The glass will have a dense structure. In the third process, the molten glass is rapidly cooled to form a powder having fine particles. When the molten glass is passed through a quenching roller and rapidly cooled, crushed glass having fine cracks is formed, and the crushed glass is subjected to a predetermined time by a ball milling method. By milling (eg, 16 hours) and sequentially passing through # 170, # 270, and # 350 sibers, a powder having a good particle size dispersion of about 6 μm or less can be made.

The conductive particles and the organic solvent are mixed in the powder at a predetermined ratio to form a paste or slurry containing the conductive particles. The conductive particles and the organic solvent (Vehicle) are mixed at a ratio to make a paste containing the conductive particles. At this time, the organic solvent (Vehicle) is referred to as BCA (Butyl-Carbitol-Acetate; "BCA"), BC (Butyl-Carbitol; "BC") and EC (Ethyl-Cellulose; "EC" The organic solvent mixed with a predetermined ratio is used, and since the viscosity of the paste is changed by the amount of EC, it affects the rheology and sintering characteristics, so the mixing ratio of EC is preferably 10%. In addition, the mixing ratio of BCA is 60%, BC is preferably 20%. At this time, the viscosity of the paste is preferably 70000-100,000 CPS, and the viscosity of the slurry is preferably 700-1,000 CPS. In addition, the paste is used for screen printing, and the slurry is used for tape casting or spin coating.

A paste containing conductive particles is coated on the glass substrate on which the conductive layer is formed to a predetermined thickness to form an insulator layer (Step 23), and then sintered at a predetermined temperature for a predetermined time (Step 24). The paste or slurry containing conductive particles is formed on the formed glass substrate to have a predetermined thickness by selecting one of screen printing, tape casting, and spin coating methods. In this case, as the material of the conductive particles, carbon compounds such as graphite, metals, conductive materials, and the like are used. In addition, the glass substrate on which the insulator layer is formed is dried in a dry oven for a predetermined time (for example, 20 minutes), and then the dried glass substrate is introduced into a heating furnace and sintered according to the crystallization temperature to form an insulator layer. At this time, the organic substance contained in the paste is erased in the dry oven. The sintering temperature determines the crystallization temperature from the DTA (Differential Thermal Analysis; "DTA") analysis of the mixed powder, and in the case of SiO ₂ -ZnO system by setting the sintering temperature to 500-580 ℃ For example, 15-30 minutes). Accordingly, an insulator layer is formed that satisfies the thermal requirements.

Second embodiment

In the second embodiment of the present invention, the composition of the insulator and the manufacturing method thereof will be described. The insulator has a composition of a mixed powder in which the oxide filler powder is mixed with the SiO ₂ -ZnO-based amorphous glass powder in a predetermined ratio. The composition ratio of the SiO ₂ -ZnO-based amorphous glass powder is shown in Table 1, and the composition ratio of the filler added to the SiO ₂ -ZnO-based amorphous glass is shown in Table 2. Composition ratio in Table 2 was determined by the weight of SiO ₂ -ZnO-based amorphous glass to 100% by weight.

Composition ratio of filler added to SiO ₂ -ZnO based amorphous glass Filler TiO ₂ Al ₂ O ₃ Mg ₂ Al ₃ (AlSi ₅ O ₁₈ ) LiAl (Si ₂ O ₆ ) weight% 0-15

For example, the filler added to the SiO ₂ -ZnO-based amorphous glass, Al ₂ O ₃ to form an insulator having a low coefficient of thermal expansion. In detail, the thermal expansion coefficient of amorphous glass is 101 X 10 ^-7 / ℃ and the thermal expansion coefficient of Al ₂ O ₃ is 70 X 10 ^-7 / ℃, the insulator formed by adding Al ₂ O ₃ to the amorphous glass The coefficient of thermal expansion is 85-90 × 10 ⁻⁷ / ° C., approximating the thermal expansion coefficient of 83-85 × 10 ⁻⁷ / ° C. of the glass substrate (soda lime glass). Meanwhile, TiO ₂ , Al ₂ O ₃ , Mg ₂ Al ₃ (AlSi ₅ O ₁₈ ) and LiAl (Si ₂ O ₅ ) may be added to the amorphous glass to form an insulator, and according to the characteristics required for the insulator TiO ₂ , Al ₂ O ₃ , Mg ₂ Al ₃ (AlSi ₅ O ₁₈ ), V ₂ O ₅ and LiAl (Si ₂ O ₅ ) may be selectively added to glass to form an insulator.

Referring to FIG. 4, there is shown a diagram illustrating an insulator manufacturing process of a printable field emission device according to a second embodiment of the present invention.

SiO ₂ -ZnO-based amorphous glass powder and the filler powder is mixed to form a mixed powder (step 31) The powder forming process of the SiO ₂ -ZnO-based amorphous glass is the same as in Fig. 3 and will not be described in detail. In addition, the filler is selectively added to the amorphous glass powder according to the composition ratio of Table 2 to form a mixed powder by mixing a predetermined time (for example, 7 hours) in a tumbling mixer.

Conductive particles and organic solvent (Vehicle) are mixed in the mixed powder at a predetermined ratio to form a paste or slurry containing the conductive particles (step 32). When the conductive powder and the organic solvent (Vehicle) is mixed in a predetermined ratio to the mixed powder to form a paste state. At this time, the organic solvent (Vehicle) is referred to as BCA (Butyl-Carbitol-Acetate; "BCA"), BC (Butyl-Carbitol; "BC") and EC (Ethyl-Cellulose; "EC" The organic solvent mixed with a predetermined ratio is used, and since the viscosity of the paste is changed by the amount of EC, it affects the rheology and sintering characteristics, so the mixing ratio of EC is preferably 10%. In addition, the mixing ratio of BCA is 60%, BC is preferably 20%. At this time, the viscosity of the paste is preferably 70000-100,000 CPS, and the viscosity of the slurry is preferably 700-1,000 CPS. In addition, the paste is used for screen printing and the slurry is used for tape casting or spin coating.

A paste containing conductive particles is coated on the glass substrate on which the conductive layer is formed to a predetermined thickness to form an insulator layer (Step 23), and then sintered at a predetermined temperature for a predetermined time (Step 24). The paste or slurry containing conductive particles on the formed glass substrate is formed to have a predetermined thickness by selecting one of screen printing, tape casting and spin coating methods. In this case, as the material of the conductive particles, carbon compounds such as graphite, metals, conductive materials, and the like are used. In addition, the glass substrate on which the insulator layer is formed is dried in a dry oven for a predetermined time (for example, 20 minutes), and then the dried glass substrate is introduced into a heating furnace and sintered according to the crystallization temperature to form an insulator layer. At this time, the organic substance contained in the paste is erased in the dry oven. The sintering temperature determines the crystallization temperature from the DTA (Differential Thermal Analysis; "DTA") analysis of the mixed powder, and in the case of SiO ₂ -ZnO system by setting the sintering temperature to 500-580 ℃ For example, 15-30 minutes). Accordingly, an insulator layer is formed that satisfies the thermal requirements.

On the other hand, the characteristics of the insulator layer formed by adding a filler to the SiO ₂ -ZnO-based amorphous glass by the above manufacturing method is shown in Table 3.

Characteristics of Insulator Layer Added with Filler in SiO ₂ -ZnO-based Amorphous Glass Withstand voltage (KV) 1.5 Thermal expansion coefficient (10 ^-7 / ℃) 78-87 Sintering Temperature (℃) 500-580 Surface Roughness (100㎛, Å) 3000

The insulator layer formed by the above method minimizes the influence of heat and improves the coefficient of thermal expansion.

Referring to FIG. 5, the field emission device according to the present invention includes a conductive layer 14 formed on the glass substrate 12 to have conductivity and an insulating layer formed on the conductive layer 14 to have a predetermined thickness. 16) and conductive particles 18 distributed within the insulating layer 16 to emit electrons. In this case, as the material of the conductive particles, carbon compounds such as graphite, metals, conductive materials, and the like are used. The insulating layer 18 is an amorphous SiO ₂ -ZnO-based glass or a SiO ₂ -ZnO system is formed by an amorphous glass composition was added to the filler in the sealing of the column and attached to each other, the upper and lower glass substrates that may occur during the driving (Sealing) process It prevents the paste from deteriorating due to the temperature heated at, thereby satisfying the thermal requirements.

As described above, the insulator composition according to the present invention has an advantage of minimizing the influence of heat.

In addition, the field emission device using the insulator composition according to the present invention has the advantage of minimizing the influence of heat and improving the thermal expansion characteristics.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (10)

In the insulator composition for a field emission device, Insulator composition for a field emission device, characterized in that the insulator composition contains a SiO ₂ -ZnO-based glass. The method of claim 1, The insulator composition is an insulator composition for a field emission device, characterized in that the oxide powder is formed by mixing the SiO ₂ -ZnO-based glass powder with a filler. The method of claim 1, The SiO ₂ -ZnO-based glass is 20 to 40% by weight of ZnO, 15 to 23% by weight of SiO ₂ , 10 to 20% by weight of B ₂ O ₃ , 3 to 8% by weight of Na ₂ O, 2 to 10 wt% K ₂ O, 1 to 5 wt% CaO, 1 to 4 wt% Al ₂ O ₃ , 0 to 25 wt% PbO and 0 to 5 wt% Li ₂ O And 0 to 4% by weight of Sb ₂ O ₃ and 0 to 2% by weight of As ₂ O ₃ . The method of claim 2, For the field emission device characterized in that the filler comprises at least one or more of 0 to 15% by weight of Al ₂ O ₃ , TiO ₂ , Mg ₂ Al ₃ (AlSi ₅ O ₁₈ ) and LiAl (Si ₂ O ₆ ) Insulator composition. In the printable field emission device, A field emission device comprising: an SiO ₂ -ZnO-based glass having an insulating layer formed to a predetermined thickness. The method of claim 5, The insulating layer is a field emission device, characterized in that formed by adding a filler of 0 to 15% by weight to the SiO ₂ -ZnO-based glass. The method of claim 5, The SiO ₂ -ZnO-based glass is 20 to 40% by weight of ZnO, 15 to 23% by weight of SiO ₂ , 10 to 20% by weight of B ₂ O ₃ , 3 to 8% by weight of Na ₂ O, 2 to 10 wt% K ₂ O, 1 to 5 wt% CaO, 1 to 4 wt% Al ₂ O ₃ , 0 to 25 wt% PbO and 0 to 5 wt% Li ₂ O And 0 to 4% by weight of Sb ₂ O ₃ and 0 to 2% by weight of As ₂ O ₃ . The method of claim 6, The filler is a field emission device characterized in that it comprises at least one or more of 0 to 15% by weight of Al ₂ O ₃ , TiO ₂ , Mg ₂ Al ₃ (AlSi ₅ O ₁₈ ) and LiAl (Si ₂ O ₆ ). Forming amorphous glass powder, Forming a paste by mixing conductive particles and an organic solvent in a predetermined ratio with the powder; Applying the paste to a substrate having a conductive layer to a predetermined thickness to form an insulating layer; And sintering the substrate at a predetermined temperature for a predetermined time. The method of claim 9, Method for producing an insulator for a field emission device characterized in that it further comprises the step of mixing the amorphous glass powder with an oxide powder of 0 to 15% by weight as a filler to form a mixed powder.