KR100708748B1 - Plasma display panel - Google Patents

Abstract

The present invention is to minimize the occurrence of spots of the mesh marks due to the bending of the dielectric layer, and the first and second substrates are opposed to each other, the plurality of discharge cells interposed between the first substrate and the second substrate and A conductor formed on a surface of the first substrate facing the second substrate, the conductors including first and second layers sequentially formed, and a first dielectric layer covering the conductors; The distance between adjacent conductors is 80 占 퐉 or more, and relates to a plasma display panel that is 50% or less of the cell pitch of the discharge cell.

Description

Plasma display panel {Plasma display panel}

1 is an exploded perspective view of a plasma display panel according to an exemplary embodiment of the present invention.

2A and 2B are cross-sectional views and SEM photographs of the bus electrodes of FIG. 1, respectively.

3 is a cross-sectional view showing a distance between a bus electrode and a distance between a bus electrode and an external light absorbing member in a plasma display panel according to an exemplary embodiment of the present invention.

4 is a cross-sectional view of a plasma display panel having a pair of external light absorbing members, according to another exemplary embodiment of the present invention.

<Brief description of the major symbols in the drawings>

10: first substrate 20: second substrate

11: address electrode 12: first dielectric layer

13: partition 14: phosphor layer

15: photoresist film 21, 22: discharge sustaining electrode pair

23,25: transparent electrode 24,26: bus electrode

27: external light absorbing member 28: second dielectric layer

29: MgO Membrane

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (PDP), and more particularly, to a plasma display panel which can prevent a screen from being stained due to a bend in a dielectric layer.

Recently, a device employing a plasma display panel as a flat panel display device has a large screen and has excellent characteristics of high definition, ultra-thin, light weight, and wide viewing angle, and is easier to manufacture than other flat panel display devices. It is attracting attention as a large flat panel display device.

A typical plasma display panel has a pair of substrates opposed to each other. Address electrodes and a dielectric layer are sequentially formed on one of the substrates, and partition walls are formed on the dielectric layer to maintain a discharge distance and to prevent electro-optical crosstalk between pixels, and at least one side of the discharge space partitioned by the partition walls. Phosphor layer is formed in. Discharge sustaining electrodes and a dielectric layer are sequentially formed on the other substrate, and a protective film such as an MgO layer is formed on the surface of the dielectric layer. The plasma display panel discharges by applying a voltage to the address electrodes and the discharge sustain electrodes.

In the conventional plasma display panel, the dielectric layer covers the discharge sustaining electrodes and the address electrode. At this time, the curvature of the electrode may be reflected and the curvature may appear on the dielectric layer. During the bending of the dielectric layer, the dielectric layer formed on the substrate on which the image is realized, that is, the bent portion of the dielectric layer covering the discharge sustaining electrodes remains more severe than other portions of the printing mask during printing, so that the mesh marks are formed when the panel is discharged. It will remain stained.

This problem becomes more problematic in recent years by forming a light absorbing member for improving contrast between discharge sustaining electrodes. In particular, when the light absorbing member is formed in the same shape as the discharge sustaining electrode, the gap between the discharge sustaining electrodes and the gap between the discharge sustaining electrode and the light absorbing member are narrowed to further cause the above-described bending phenomenon.

SUMMARY OF THE INVENTION The present invention has been made to solve the above and other problems, and an object of the present invention is to provide a plasma display panel capable of minimizing stain generation of mesh marks due to bending of a dielectric layer.

According to the present invention, a plurality of discharge cells interposed between the first substrate and the second substrate, the first substrate and the second substrate, and the second substrate of the first substrate are formed on the surface facing the second substrate. And a conductor including sequentially formed first and second layers, and a first dielectric layer covering the conductors, wherein an interval between adjacent conductors of the conductors is greater than or equal to 80 μm The present invention provides a plasma display panel having 50% or less of the cell pitch of the discharge cells.

The first layer may be provided as a light absorbing member, and the second layer may be provided as a light reflecting member.

The conductors may include a discharge sustaining electrode.

The discharge sustaining electrode may include a transparent electrode and a bus electrode, and the conductors may include the bus electrode.

The conductors may include an external light absorbing member positioned between each of the discharge cells.

The gap between the conductors may be a gap at a position corresponding to 1/2 of the highest height of the conductor.

The conductors may have an edge- curl shape whose thickness at the edge is thicker than the thickness at the center.

The cell pitch of the discharge cell may be a cell pitch in a direction orthogonal to the extending direction of the conductors.

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

Referring to FIG. 1, the plasma display panel of the present invention has a first substrate 10 and a second substrate 20 opposed to each other, and between the first and second substrates 10, 20. Discharge gases, such as neon Ne and Xen, are filled.

A partition 13 is interposed between the first substrate 10 and the second substrate 20, and the space between the first and second substrates 10 and 20 is defined by the partition 13. It is divided into a plurality of discharge cells (C).

The partition 13 may be formed of a dielectric commonly used in a plasma display panel, and may be formed by various methods such as screen printing, sand blasting, dry film, and photolithography. The partition wall 13 may be formed in a lattice shape as shown in FIG. 1, but is not necessarily limited thereto, and may be formed in various shapes such as a honeycomb shape and a circular shape.

At least two electrodes are formed to intersect with each other around the discharge cell C partitioned by the partition 13 to generate a discharge. According to a preferred embodiment of the present invention, an address is provided on the first substrate 10. The electrode 11 may be disposed, and the discharge sustaining electrode pairs 21 and 22 may cross the address electrode 11 and may be disposed in parallel to each other on the second substrate 20. One unit discharge cell C is formed where the discharge sustaining electrode pairs 21 and 22 and the address electrode 11 cross each other.

The address electrode 11 may be formed so as not to be exposed to the discharge cell C. According to a preferred embodiment of the present invention, the address electrode 11 is covered on the first substrate 10. The first dielectric layer 12 may be formed. The first dielectric layer 12 is preferably white in color so as to improve the brightness of the entire panel. The address electrode 11 may be formed in a stripe pattern parallel to the direction of one side of the first substrate 10, but is not necessarily limited thereto, and may be formed in various patterns such as a zigzag pattern and an oblique pattern. However, even in this case, it is preferable that the entire extension direction is substantially parallel to the direction of one side of the first substrate 10.

The discharge sustaining electrode pairs 21 and 22 are arranged in pairs with the X electrode 21 and the Y electrode 22. The X electrode 21 and the Y electrode 22 extend parallel to the direction substantially perpendicular to the extending direction of the address electrode 11.

The X electrodes 21 and X electrodes 22 are transparent electrodes 23 and 25 formed of indium tin oxide (ITO), which are transparent conductors, respectively, and electricity connected to each of the transparent electrodes 23 and 25. The bus electrodes 24 and 26 may be formed of a material having excellent conductivity. According to a preferred embodiment of the present invention according to FIG. 1, the transparent electrodes 23 and 25 are formed in islands for each discharge cell C, and the bus electrodes 24 and 26 are addressed. The electrode 11 is formed in a stripe shape orthogonal to the electrode 11, but is not limited thereto. The transparent electrodes 23 and 25 may also be formed to be connected to each other in a direction orthogonal to the address electrode 11. . The pattern in which the bus electrodes 24 and 26 extend is also not limited to the stripe pattern, and may be formed in various patterns such as a zigzag pattern, a pulse wave pattern, an oblique pattern, a honeycomb pattern, and the like. However, also in this case, it is preferable that the entire extension direction is parallel to the direction orthogonal to the address electrode 11.

Between the discharge sustaining electrode pairs 21 and 22 and the discharge sustaining electrode pairs 21 and 22, an external light absorbing member 27, which is a black stripe for improving contrast, is further formed. As described later, the external light absorbing member 27 may be formed of the same material as the bus electrodes 24 and 26, and accordingly, a separate process for forming the external light absorbing member 27 is performed. This is not necessary, and as a result, production time and material cost can be reduced due to the reduction of the process.

A second dielectric layer 28 is formed on the second substrate 20 so as to cover the pair of discharge sustaining electrodes 21 and 22, and an MgO film 29 that functions as a protective film and a substantially cathode is formed thereon. Can be.

The structures and patterns of the discharge sustaining electrode pairs 21 and 22 and the address electrode 11 may be variously modified in addition to the above. The same applies to the panel.

A phosphor layer 14 may be provided on at least one surface of the discharge cell C. According to a preferred embodiment of the present invention, the first dielectric layer of the first substrate 10 having the partition wall 13 formed thereon is formed. (12) It may be formed on the upper side and the side wall of the partition wall (13). The phosphor layer 14 may be formed in red (R), green (G), and blue (B) colors for each discharge space partitioned by the partition wall 13 to implement a color screen.

Meanwhile, in the present invention, the bus electrodes 24 and 26 may be formed in a double layer structure as shown in FIG. 2A to obtain two effects of preventing luminance reduction and improving contrast. That is, the first layers 24a and 26a, which are black electrodes in which black additives are mixed, are formed adjacent to the second substrate 20 where the image is embodied to absorb external light flowing from the outside of the second substrate 20. The contrast is enhanced, and the second layers 24b and 26b, which are white electrodes, are formed of a light reflective high conductivity material on the first layers 24a and 26a, so that the light emitted from the discharge cells is transferred to the first layer. It is absorbed by 24a) 26a and prevents brightness from falling.

These bus electrodes 24 and 26 are manufactured in the following manner.

First, a black conductive paste is printed on the second substrate 20 so as to form the first layers 24a and 26a and dried in infrared. Then, a white conductive paste is printed on the black conductive face so as to form second layers 24b and 26b and dried in infrared. Next, a DFR film or a photoresist in which the patterns of the bus electrodes 24 and 26 are formed is coated on the white conductive paste, and then exposed using ultraviolet rays. Then, the pattern of the bus electrodes 24 and 26 is formed through development exaggeration, and then fired.

However, at this time, the black electrode whose bus electrodes 24 and 26 are the first layers 24a and 26a is weaker to the developing solution than the white electrode which is the second layers 24b and 26b, and thus develops more. As a result, as shown in FIG. 2A, an undercut (U) in which a portion adjacent to the first substrate 20 of the first layers 24a and 26a is cut is generated. In the case of the double layer, ultraviolet rays are exposed to the first layers 24a and 26a during the exposure process, but the black electrodes of the first layers 24a and 26a are the second layers 24b and 26b. Since less ultraviolet light is emitted than the white electrode of), curing by ultraviolet light is less than that of the second layers 24b and 26b, so that the first layers 24a and 26a are better developed during development, so that undercuts U occur. do.

 In addition, due to the undercut (U), when contracted during firing, both ends of the bus electrodes 24 and 26 with the undercut U are not subjected to the contraction force to the lower side, while the center portion is the first layer ( Since 24a) and 26a are vertically contracted and subjected to contraction force to the bottom, an edge-curl phenomenon occurs in which the unsupported end E rises and the center of the force descends. The bus electrodes 24 and 26 have a thicker edge t2 than the thickness t1 of the central portion thereof.

2B is a photograph of bus electrodes 24 and 26 with undercuts and edge curls generated.

As shown in FIG. 2A, the external light absorbing member 27 formed of the same material as the bus electrodes 24 and 26 may be similarly described.

After forming the bus electrodes 24 and 26 and the external light absorbing member 27 formed on the second substrate 20 as shown in FIG. 2A, the second dielectric layer 28 is formed to cover the second substrate 20. The second dielectric layer 28 is coated with a dielectric material using a screen mask through front printing, and is formed through a printing, drying, and baking process.

However, at this time, if the spacing between the bus electrodes 24 and 26 or the spacing between the bus electrodes 24 and 26 and the external light absorbing member 27 becomes too narrow, the influence of the above-described edge curl may be affected. In response, a step or bending occurs in the second dielectric layer 28. In the stepped portion or the bent portion formed in the second dielectric layer 28, the mesh mark of the screen mask remains more severe than the other place, and there is a problem that the mesh mark appears as a stain during discharge.

The inventors have found that even when the above-described phenomenon such as edge curl occurs, the gap between the bus electrodes 24 and 26 or the gap between the bus electrodes 24 and 26 and the external light absorbing member 27 are not limited. When the spacing was adjusted, it was found that the second dielectric layer 28 was formed relatively uniformly, and thus the mesh spot defect did not occur.

First, as shown in FIG. 3, when the bus electrode 24 of the X electrode and the bus electrode 26 of the Y electrode are disposed, and the external light absorbing member 27 is disposed outside the electrode pairs 24 and 26. The distance W1 between the bus electrodes 24 and 26 or the distance W2 between the bus electrode 26 and the external light absorbing member 27 is 80 μm or more.

At this time, the intervals W1 and W2 are between the respective members at the point of the highest thickness of each member, that is, the thickness t3 = t2 / 2 which is half of the thickness t2 of the above-described edge. The interval is measured.

Table 1 below shows the number of mesh stain defects according to the distance W2 between the bus electrode 26 and the external light absorbing member 27, and shows the number of defect occurrences among 100 sheets. At this time, the thickness t1 of the bus electrode 26 and the external light absorbing member 27 is about 5 to 6 μm, and the thickness of the edge curl, that is, the thickness t2 minus the thickness t1 from the edge thickness t2. Is about 1 to 3 µm.

W2 (㎛) 60 70 80 90 Number of mesh stain defects (sheets) 80 30 0 0

As can be seen from Table 1, when the distance (W2) between the bus electrode 26 and the external light absorbing member 27 is 80㎛ or more it can be seen that the mesh unevenness is hardly generated.

This interval W2 is preferably set to 50% or less of the cell pitch of the discharge cells. That is, as shown in FIG. 1, it is preferable to adjust the gap W2 within about 50% of the cell pitch A in the direction orthogonal to the direction in which the bus electrodes 24 and 26 extend. This is because if the gap W2 is larger than 50% of the cell pitch A, the actual design of the discharge cell is almost impossible.

The above experiment is for the spacing W2 between the bus electrode 26 and the external light absorbing member 27, but the spacing W1 between the bus electrodes 24 and 26 formed in the same manner as the external light absorbing member 27. Of course, the same applies to.

4 shows an example in which a pair of external light absorbing members 27 and 27 'is formed outside the bus electrodes 24 and 26, and in this case, the external light absorbing members 27 and 27' are also shown. It is preferable to make it the space | interval W3 between 80 micrometers or more and 50% or less of the cell pitch A.

According to the present invention, it is possible to reduce the production cost by forming an external light absorbing member that can improve the contrast with the bus electrode. At the same time, even when a phenomenon such as edge curl occurs in the external light absorbing member and the bus electrode, it is possible to reduce the occurrence of mesh stain defects.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (8)

First and second substrates opposed to each other; A plurality of discharge cells interposed between the first substrate and the second substrate; Conductors formed on a surface of the first substrate facing the second substrate, the conductors including first and second layers sequentially formed; And A first dielectric layer covering the conductors; And a distance between adjacent ones of the conductors is 80 µm or more and 50% or less of the cell pitch of the discharge cell. The method of claim 1, The first layer is provided with a light absorbing member, the second layer is provided with a light reflecting member. The method of claim 1, And the conductors include a discharge sustaining electrode. The method of claim 3, The discharge sustaining electrode includes a transparent electrode and a bus electrode, The conductors include the bus electrode. The method of claim 1, The conductors include an external light absorbing member positioned between each of the discharge cells. The method according to any one of claims 1 to 5, And the spacing between the conductors is a spacing at a position corresponding to one half of the highest height of the conductor. The method according to any one of claims 1 to 5, And the conductors are edge-curled in thickness at the edge thereof thicker than the thickness at the center. The method according to any one of claims 1 to 5, And a cell pitch of the discharge cells is a cell pitch in a direction orthogonal to the extending direction of the conductors.

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