CN101308755A - Plane emission type cathode structure of field emission display - Google Patents

Abstract

A planar emission cathode structure of a field emission display, the cathode structure has a cathode substrate, a plurality of cathode units are arranged on the cathode substrate, the cathode units include an emitter layer, a gate layer and a dielectric layer, wherein the emitter layer and the gate layer are arranged on the cathode substrate in the same plane, and are separated from each other and form a gap, and in addition, the dielectric layer is arranged in the gap formed by the emitter layer and the gate layer, and forms a gap with the emitter layer and the gate layer respectively without being adjacent, so as to change the electric field distribution state of the emitter layer and the gate layer.

Description

Plane Emitting Cathode Structure of Field Emission Display

technical field

The invention relates to a field emitter, in particular to a coplanar cathode plate structure.

Background technique

In recent years, flat panel display (FPD) has been widely used in display requirements of different sizes due to its light and thin features, and even better than traditional TV in terms of image quality, resolution and brightness. , as small as mobile phone screens, as large as outdoor billboards, the application of flat-panel displays can be seen, making flat-panel displays attract much attention in the market.

Therefore, various types of flat-panel displays are continuously launched on the market, including liquid crystal displays (LCDs), plasma displays (PDPs), organic light-emitting diode displays (OLEDs), and field emission displays (FEDs); especially field emission displays (FED) is one of the types of flat-panel displays emerging in recent years. Its principle is to use the cathode electron emission source set in the internal structure to generate electron beams, thereby hitting the corresponding fluorescent layer to generate bright light.

The field emission display of the three-pole structure in the traditional technology includes an anode plate, a cathode plate, and a gate layer between the cathode and anode plates, wherein the gate layer provides a potential for attracting electrons generated by the cathode plate, and then the anode conductive layer A high potential is provided to provide the accelerated kinetic energy of electrons to strike the anode plate to produce bright light.

However, although the above-mentioned conventional structure can make the field emission display normally emit light, because the design of the gate layer is directly arranged between the cathode plate and the anode plate, and is adjacent to the emitter provided by the cathode plate, resulting in It is found that the cathode plate is relatively complicated to manufacture and the cost is high; therefore, in order to reduce the cost and improve the defects of the above-mentioned structure in the prior art, a kind of emitter and grid are developed on the same plane. The cathode structure, as disclosed in US Patent Publication No. US6891320, changes the traditional cathode structure formed by lamination, not only is easier in the manufacturing process, but also reduces its manufacturing cost.

The above-mentioned coplanar structure design forms the emitter and the grid on the cathode substrate, which has the advantages of reducing cost and simplifying the manufacturing process, but it has an impact on the electric field of the electrons generated by the grid attracting the emitter along the horizontal direction; The vector of the electric field on the surface of the pole directly affects the quantity and direction of the electrons emitted by the field. Under the same potential condition, the larger the distance between the emitter and the grid, the smaller the intensity of the electric field acting on the surface of the emitter. The electron generation efficiency is reduced, which directly affects the luminous effect of the field emitter.

Although the distance formed between the emitter and the gate can be reduced to less than a few microns by using the semiconductor manufacturing process, it will relatively increase its production cost, and under the same potential, if the distance between the emitter and the gate is too small, the Under the interaction of two electric fields, part of the free electrons released by the emitter will be attracted by the gate and cannot be accelerated to the anode, but will move towards the gate instead, resulting in a leakage current phenomenon. If a thick film manufacturing process is used, although the manufacturing cost can be reduced, the distance between the emitter and the grid will be affected by the accuracy of the printed panel and must be kept at more than tens of microns, otherwise the emitter and grid will be generated. The flatness of the structure or the deformation of the material after sintering makes the emitter and the grid unable to function. In order to make up for the problem of the excessive distance between the emitter and the grid caused by this manufacturing process, the potential of the anode plate must be increased to obtain The greater electric field strength of the anode plate to the cathode plate. Therefore, no matter which manufacturing process is selected, there will be defects applied to the coplanar structure of the cathode plate, and it is necessary to find a new way to solve it.

Contents of the invention

In view of the above defects, the present invention mainly provides a planar emission cathode structure of a field emission display, the cathode structure has a cathode substrate, and a plurality of cathode units are arranged on the cathode substrate, and the cathode units include an emitter layer, a grid layer and a dielectric layer, wherein the emitter layer and the gate layer are coplanarly arranged on the cathode substrate, and are separated from each other and form intervals; in addition, the dielectric layer is arranged on the layer formed by the emitter layer and the gate layer and form gaps with the emitter layer and the gate layer respectively without being adjacent to each other, thereby forming a coplanar structure of the cathode structure.

Compared with the prior art, the beneficial effect of the planar emission cathode structure of the field emission display of the present invention is that by setting the dielectric The electric field distribution state of the emitter layer and the gate layer can be changed, and at the same time, the cost of the manufacturing process can be reduced because the coplanar structure can be directly fabricated on the cathode substrate.

Description of drawings

Fig. 1 is a structural sectional view of an embodiment of the present invention;

Fig. 2 is a structural sectional view of another embodiment of the present invention;

Fig. 3 (A) to Fig. 3 (D) are the electric field distribution schematic diagrams of the present invention;

FIG. 4 is a graph of emitter discharge current and gate voltage in the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

Cathode Structure 1 Cathode Substrate 11

Cathode Unit 12 Emitter Layer 121

Gate layer 122 Dielectric layer 123

Cathode conductive layer 124 Interval 125

Detailed ways

The content of the present invention will be described below in conjunction with the accompanying drawings.

Fig. 1 is a structural sectional view of an embodiment of the present invention. As shown in FIG. 1 , the cathode structure 1 has a cathode substrate 11 on which a plurality of cathode units 12 are arranged so as to correspond to the anode. Each cathode unit 12 includes an emitter layer 121, a gate layer 122, a dielectric layer 123 and the cathode conductive layer 124, wherein the emitter layer 121 and the gate layer 122 are coplanarly arranged on the cathode substrate 11, and the emitter layer 121 and the gate layer 122 are respectively electrically connected to the cathode conductive layer 124, thereby serving as a conductive path , and the emitter layer 121 and the gate layer 122 are separated from each other on the cathode substrate 11 and form a space 125. In this embodiment, the space 125 between the emitter layer 121 and the gate layer 122 is maintained at 50 μm. In addition, on the cathode substrate The thickness of the emitter layer 121 and the gate layer 122 on 11 is between 1 μm and 25 μm.

In addition, the dielectric layer 123 is disposed in the space 125 formed between the emitter layer 121 and the gate layer 122, and is disposed on the cathode substrate 11 coplanar with the emitter layer 121 and the gate layer 122, while the dielectric layer 123 maintains a certain gap with the adjacent emitter layer 121 and gate layer 122, and the dielectric layer 123 does not connect with the emitter layer 121 or the gate layer 122, wherein the gap is kept between 5-15 μm, and In this embodiment, the dielectric layer 123 is made of a material containing glass components, such as glass glue, and this material is an insulating material with a dielectric constant greater than or equal to 7. In addition, the thickness of the dielectric layer 123 is equal to that of the emitter layer 121. 0.5 to 1.5 times the thickness, as shown in Figure 1 in this embodiment, the thickness of the dielectric layer 123 is greater than the thickness of the emitter layer 121 and the gate layer 122, or as shown in Figure 2, the thickness of the dielectric layer 123 The thickness is smaller than the thickness of the emitter layer 121 and the gate layer 122 .

FIG. 3(A) and FIG. 3(B) are comparison diagrams of electric field distribution in the present invention. Fig. 3 (A) is the distribution of its electric field under the situation without dielectric layer 123, and Fig. 3 (B) is the distribution of its electric field under the situation that there is dielectric layer 123, in Fig. 3 (A), this electric field distribution Concentrated in the gap 125 formed by the emitter layer 121 and the gate layer 122, so that the electrons generated by the emitter layer 121 cannot be completely directed to the corresponding anode, resulting in a leakage current phenomenon; and in FIG. 3(B) , it can be seen that the dielectric layer 123 is provided in the gap 125 formed by the emitter layer 121 and the gate layer 122, and the electric field distribution density of the gap 125 is reduced accordingly, so that after the electrons in the emitter layer 121 are attracted, the It is successfully attracted by the potential of the anode and hits the anode. Therefore, the dielectric layer 123 is coplanarly arranged between the emitter layer 121 and the gate layer 122, which not only simplifies the manufacturing process of the cathode structure 1, but also makes the dielectric layer 123 can also be used as a barrier between the emitter layer 121 and the gate layer 122, changing the electric field distribution density between the emitter layer 121 and the gate layer 122, thereby blocking electrons in the emitter layer 121 from moving to the gate layer 122, reducing the cathode Leakage current phenomenon on structure 1; In addition, in conjunction with Fig. 3 (C) and Fig. 3 (D), the dielectric layer 123 of different dielectric constants is set, as the dielectric layer set in Fig. 3 (D) of the present embodiment The dielectric constant of 123 is greater than that of the dielectric layer 123 in FIG. 3(C), so that the electric field distribution density adjacent to the emitter 121 in FIG. 3(D) is greater than the electric field distribution density adjacent to the emitter 121 in FIG. 3(C). .

Therefore, in conjunction with FIG. 3(B) to FIG. 3(D) and FIG. 4, under the influence of the dielectric layer 123 with different dielectric constants, the electric field distribution density of the emitter layer 121 and the gate layer 122 will be changed, as shown in FIG. As shown in FIG. 4 , when the same voltage is applied to the gate layer 122 , under the influence of the dielectric layer 123 with a larger dielectric constant, the current released by the emitter layer 121 is larger.

The above-mentioned embodiment is a preferred embodiment of the present invention, but it cannot limit the implementation scope of the present invention. Equivalent changes or modifications made according to the claims of the present invention and the content of the specification should all fall within the scope of the patent of the present invention.

Claims (9)

1. A planar emission type cathode structure of a field emission display, comprising: cathode substrate; A plurality of cathode units are arranged on the cathode substrate, and the cathode units include: emitter layer; a gate layer, coplanar with the emitter layer, disposed on the cathode substrate, and corresponding to and separated from the emitter layer, while forming a fixed interval; A dielectric layer is disposed in the interval formed by the emitter layer and the gate layer, and is disposed on the cathode substrate coplanar with the emitter layer and the gate layer, and the dielectric layer is disposed on the cathode substrate coplanarly with the gate layer. The emitter layer and the gate layer respectively form gaps. 2. The planar emitting cathode structure of a field emission display as claimed in claim 1, wherein the interval is 50 μm. 3. The planar emission cathode structure of a field emission display according to claim 1, wherein the thickness of the emitter layer and the gate layer is between 5 μm˜15 μm. 4. The planar emission cathode structure of a field emission display as claimed in claim 1, wherein the dielectric layer is composed of a glass-containing material. 5. The planar emission cathode structure of a field emission display as claimed in claim 1, wherein the dielectric layer is made of glass glue. 6. The planar emission cathode structure of a field emission display as claimed in claim 1, wherein the dielectric constant of the dielectric layer is greater than or equal to 7. 7. The planar emission cathode structure of a field emission display according to claim 1, wherein the thickness of the dielectric layer is between 0.5 times and 1.5 times the thickness of the emitter layer. 8. The planar emission cathode structure of a field emission display as claimed in claim 1, wherein the thickness of the dielectric layer is greater than that of the emitter layer. 9. The planar emission cathode structure of a field emission display as claimed in claim 1, wherein the thickness of the dielectric layer is smaller than that of the emitter layer.

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