KR100464295B1 - Field emission display device and manufacturing method - Google Patents

Abstract

The field emission display device according to the present invention includes a back substrate on which a cathode, an insulating layer, a gate, and a micro tip are formed, and a front substrate in which anodes and phosphors are sequentially formed on surfaces facing the back substrate at regular intervals. In the field emission display device having a black matrix, the black matrix material is filled between the anodes. The method for manufacturing the field emission display device may include depositing an ITO material on a front substrate, forming a photoresist pattern on the front substrate on which the ITO material is deposited, and using the photoresist pattern as a mask. Forming an ITO anode on the stripe, depositing a metal oxide for the black matrix on the exposed portions of the photoresist and the front substrate, and removing the photoresist and the metal oxide for the black matrix deposited on the photoresist by a lift off technique. It includes a step.

Description

Field emission display device and manufacturing method thereof

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission display device and a manufacturing method thereof, and more particularly, to a field emission display device having a black matrix and a method of manufacturing the same.

Field emission displays (FEDs) are flat panel display devices such as liquid crystal display panels (LCDs), plasma display panels (PDPs), fluorescent display devices (VFDs), and the like. In particular, low power consumption, wide viewing angles, temperature safety and Due to the features such as thin film, it is widely attracting attention as a next generation display device.

1 is a schematic cross-sectional view of a conventional field emission display device. As shown, the field emission display device includes a cathode plate 1 having a cathode 12, an insulating layer 13, a gate 14, and a microtip 15 formed on a rear transparent flat plate 11; An anode plate 2 having an anode 22 and a phosphor 23 formed on the front transparent plate 21 is included.

In more detail, a plurality of cathodes 12 are formed on the rear transparent flat plate 11 of the anode plate 1, and a plurality of microtips 15 are formed on the cathode 12 in an array form. In particular, these microtips 15 are formed in the through-holes of the insulating layer 13 formed on the cathode 12. The gate 14 is formed on the insulating layer 13. On the other hand, the anodes 22 are formed on the front transparent plate 21 of the anode plate 2, and the phosphors 23 for each color are coated on the anodes 22 so as to face the microtips 15, respectively. It is. The negative electrode plate 1 and the positive electrode plate 2 are spaced at a predetermined distance by a spacer (not shown), and the circumference thereof is sealed to maintain the inside in a high vacuum state.

When the micro tip 15 array of the field emission display device as described above is grounded and a constant voltage is applied between the gate 14 and the anode 12, electrons are released into the vacuum. At this time, the electrons accelerated by the voltage of the anodes 5 collide with the phosphor 23 with a constant kinetic energy. At this time, the kinetic energy of the electrons is transferred to the phosphor 23, and the phosphor 23 is excited by receiving the kinetic energy of the electrons to emit light.

In such a field effect electron emission device, the displayed color is greatly influenced by the characteristics of the phosphor 23. When the phosphor 23 of the conventional field emission display device is excited, it emits green, red or blue light, but when it is not excited and the phosphor 23 does not emit light, the phosphor 23 itself is white or It will be yellow in color. Therefore, when the phosphor 23 is not excited to realize the color of the black system, it is difficult to implement the color of the black system due to the color of the phosphor 23 itself, and thus there is a problem in that the color contrast is inferior. .

In a display device such as a cathode ray tube (CRT), in order to solve this problem, a black matrix, which is a black material, is deposited on a portion where the phosphor is not applied. However, the black matrix material used in a typical cathode ray tube is a conductive material, and is not suitable for application to field emission display devices requiring insulation properties between electrode lines.

The present invention has been made to solve the above problems, and an object thereof is to provide a field emission display device having a black matrix formed of a non-conductive material and a method of manufacturing the same.

In order to achieve the above object, the field emission display device according to the present invention, a cathode, an insulating layer, a gate and a micro-tip formed on the back substrate; And a front substrate in which anodes and phosphors are sequentially formed on surfaces facing each other at regular intervals from the rear substrate, wherein the black matrix material is filled between the anodes. do.

Here, the black matrix is preferably a metal oxide.

On the other hand, the method of manufacturing a field emission display device according to the present invention, (A) depositing an ITO material on the front substrate; (B) forming a photoresist pattern on the front substrate on which the ITO material is deposited; (C) forming an ITO anode on a stripe using the photoresist pattern as a mask; (D) depositing a metal oxide for black matrix on the exposed portion of the photoresist and the front substrate; And (e) removing the photoresist and the metal oxide for the black matrix deposited on the photoresist by a lift off technique.

In the present invention, the metal oxide for the black matrix in the step (d) is preferably to be deposited by reactive sputtering.

Hereinafter, a field emission display device and a manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings.

2 is a cross-sectional view of a field emission display device according to the present invention. As illustrated, the field emission display device according to the present invention is disposed such that the rear substrate 31 and the front substrate 41 are spaced apart at regular intervals to face each other.

Cathodes 32 are formed in a stripe shape on the rear substrate 31, and a plurality of microtips 35 are formed on the cathodes 32 in an array form. The microtips 35 are electrically connected to the cathodes 32. Meanwhile, an insulating layer 33 having a through hole is formed on the cathodes 32. The plurality of microtips 35 are accommodated in the through holes of the insulating layer 33. Gates 34 are formed on the insulating layer 33 in a stripe shape in a direction crossing the cathodes 32. At this time, an opening corresponding to the through hole of the insulating layer 33 is formed in the gate 34.

Anodes 42 are formed in a stripe shape on the corresponding back surface of the front substrate 41, and phosphor layers 43 are coated on the anodes 42. In addition, a black matrix 44 is formed between the anodes 42. This black matrix 44, which is a feature of the invention, is made of a blackish material, in particular a metal oxide film with good insulation. Such a black matrix 44 suppresses the occurrence of crosstalk by preventing the emitted light from leaking to adjacent pixels, and improves the color contrast.

The rear substrate 31 and the front substrate 41 are sealed to maintain a high vacuum between the interior spaces thereof.

In the field emission display device as described above, electrons are emitted from the microtip 35 array by a constant voltage applied to the gate 34, and the emitted electrons are accelerated and collided with the phosphor film 43. The phosphor film 43 in which the electrons collide is excited to emit light of a predetermined color (R, G, B). The phosphor film 43 which is not excited and does not emit light has a color of white or yellow color, which is an original color, but due to the black matrix 44 formed in close proximity, the color contrast is increased, so that Resolution is improved.

The manufacturing method of the field emission display device as described above is as follows.

First, the cathode 32, the insulating layer 33, the gate 34, and the microtip 35 are formed on the back substrate 31. In more detail, the ITO transparent electrode 32, the insulating layer, and the gate layer are sequentially stacked as the cathode on the rear substrate 31. Then, a photoresist mask for forming an opening is formed on the gate layer. Anisotropic etching is performed on the gate layer by a photolithography method using the photoresist mask to form a gate 34 having an opening. In this case, Reactive Ion Etching (RIE) is used for anisotropic etching.

Next, an opening is formed in the insulating layer 33 using a wet etching method. In addition, an Al isolation layer is provided on the gates 34. To this end, gradient deposition is performed such that the substrate is rotated with an electron beam evaporator to have a predetermined angle (about 75 °).

Next, in order to form the micro tip 35, molybdenum is deposited in the vertical direction while the substrate is rotated using a molybdenum (Mo) source for electron beam deposition. Then, a molybdenum tip having a sharp tip and a molybdenum layer to be removed are formed on the Al separation layer and on the cathode, respectively. The molybdenum tip formed on the cathode 32 is used as the micro tip 35, and the molybdenum layer formed on the separation layer is removed using a liftoff method.

The anode 42 on the front substrate 41 is separate from the manufacturing process of the back substrate 31 on which the cathode 32, the insulating layer 33, the gate 34, and the microtip 35 are formed as described above. The black matrix 44 and the phosphor film 43 are formed. This process will be described with reference to FIGS. 3A to 3D.

First, an ITO material 42 'is deposited on the front substrate 41, a photoresist PR is applied thereon, and then developed by a photolithography process to form a photoresist pattern (see FIG. 3A). . Then, the ITO anode 42 on the stripe is formed using the photoresist pattern as a mask (see Fig. 3B). Next, the black matrix material 44 is deposited on the exposed portion of the photoresist PR and the front substrate 41 (see FIG. 3C). As the material for the black matrix 44, a material having a black color is used. In particular, a metal oxide having good insulation is used to improve the insulation between the electrodes. At this time, reactive sputtering is used to deposit the metal oxide 44 for the black matrix. This process will be described in more detail with reference to FIG. 4.

4 schematically shows a reactive sputtering system. As shown, a target 51 made of a metal oxide is positioned above the cathode 50 of the power supply, the front substrate having an ITO anode formed thereon and a photoresist applied thereon (see FIG. 3B) 61. It is located above the anode 60 of this power supply. The distance between the target 51 and the front substrate 61 is very close, and argon and oxygen, which is a reactive gas, are mixed therebetween. When a high voltage is applied to the cathode 50 and the anode 60 to form a mixed gas of argon and oxygen into a plasma state, cations are generated. These cations are accelerated by the electric field to the opposite electrode, i.e., the target 51 to which a negative (-) voltage is applied, and collides with the target 51. Due to the exchange of momentum due to this collision, the surface atoms of the material of the target 51 are popped out to form an ITO anode pattern as vapor and deposited on the front substrate 61 coated with photoresist thereon.

As such, when the metal oxide 44 is deposited on the photoresist PR and the exposed portion of the front substrate 41, the photoresist PR and the metal oxide 44 deposited on the photoresist are removed using a lift-off method. Remove Then, as shown in FIG. 3D, an ITO anode 42 and a front substrate 41 having a black matrix metal oxide 44 formed therebetween can be obtained.

When the front substrate as described above is obtained, the phosphor film 43 is coated on the ITO anode 42.

As described above, the back substrate 31 on which the cathode 32, the insulating layer 33, the gate 34, and the microtip 35 are formed, the anode 42, the metal oxide 44 for the black matrix, and The front substrate 41 on which the phosphor film 43 is formed is completed, and the field emission display device is completed by performing an encapsulation process for maintaining the interior of the two substrates 31 and 41 in a high vacuum state.

As described above, according to the field emission display device and the manufacturing method thereof according to the present invention, since a black matrix made of a non-conductive and black metal oxide is formed between the anodes, the color contrast is increased. The resolution of the entire picture is increased.

1 is a schematic cross-sectional view showing a conventional field emission display device;

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

3A to 3D are schematic cross-sectional views illustrating, in each step, a method of forming the black matrix shown in FIG. 2;

And FIG. 4 is a schematic diagram of a system used to perform the steps shown in FIG. 3C.

<Explanation of symbols for main parts of drawing>

11, 31 ... back board 12, 32 ... cathode

13, 33 ... insulating layer 14, 34 ... gate

15, 35 ... microtips 21, 41 ... front substrate

22, 42 anodes 23, 43 phosphor membrane

44 Black Matrix 51 Target

Claims (2)

(A) depositing an ITO material on the front substrate; (B) forming a photoresist pattern on the front substrate on which the ITO material is deposited; (C) forming an ITO anode on a stripe using the photoresist pattern as a mask; (D) depositing a metal oxide for black matrix on the exposed portion of the photoresist and the front substrate; And (E) removing the photoresist and the metal oxide for black matrix deposited on the photoresist by a lift-off technique. The method of claim 1, In the step (d), the metal oxide for black matrix is deposited by reactive sputtering.