KR20080080767A - Plasma display panel and method for manufacturing thereof - Google Patents

Abstract

A plasma display panel and a manufacturing method thereof are provided to reduce power consumption of the PDP(Plasma Display Panel) by lowering a discharge voltage of the PDP. A plasma display panel includes first and second panels and first and second protective films. The first and second panels are opposed to each other with a barrier rib between them. The first protective film(100a) is formed on the first panel and contains MgO(101) doped with Si(102). The second protective film is formed on the first protective film and contains a single crystal MgO(103). The second protective film contains a dopant(104), which is selected from the group consisting of Al, Cr, H2, Si, Sc, and Gd. The dopant is contained in the second protective film at a concentration between 300 and 1000 ppm.

Description

Plasma display panel and method for manufacturing thereof

1 is a perspective view showing an embodiment of a protective film structure of a plasma display panel according to the present invention;

2 is a perspective view of a discharge cell structure of an embodiment of a plasma display panel according to the present invention;

3 is a flowchart of an embodiment of a method of manufacturing a plasma display panel according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10 lower substrate 20 address electrode

30: lower plate dielectric 40: partition wall

50a, 50b, 50c: phosphor 60: discharge gas

70: upper substrate 80a, 80b: transparent electrode

80a ', 80b': Bus electrode 90: Top dielectric

100a: first protective film 100b: second protective film

101: MgO 102: Si

103: MgO single crystal 104: dopant

The present invention relates to a plasma display panel, and more particularly, to a protective film of a plasma display panel.

With the advent of the multimedia era, display devices that can express more detailed, larger, and more natural colors are required. However, the current CRT (Cathode Ray Tube) has a limit to compose a large screen of 40 inches or more, and the LCD (Liquid Crystal Display), PDP (Plasma Display Panel), and projection TV (Television) are used for high definition video. It is rapidly developing for expansion.

The plasma display panel has a lower panel provided with an address electrode, an upper panel provided with a pair of sustain electrodes, and discharge cells defined as partition walls, and phosphors are coated in the discharge cells. Here, each discharge cell is filled with an inert gas containing a small amount of xenon and a main discharge gas such as neon, helium or a mixed gas of neon and helium. When discharge occurs in the discharge space between the upper panel and the lower panel, the vacuum ultraviolet rays generated at this time are incident on the phosphor to generate visible light, and the screen is displayed by the visible light.

The plasma display panel is driven by being divided into a reset period, an address period, and a sustain period. In the reset period, the rising ramp waveform Ramp-up is simultaneously applied to the scan electrodes. In the address period, the negative scan pulse scan is sequentially applied to the scan electrodes, and at the same time, the positive data pulse is applied to the address electrodes in synchronization with the scan pulse. In the sustain period, a sustain pulse sus is alternately applied to the scan electrodes and the sustain electrodes.

The above-described plasma display panel has a spotlight as a display device because of its thin and light structure.

Here, a dielectric layer is formed on the upper panel and the lower panel of the plasma display panel to protect the sustain electrode pair and the address electrode, respectively. However, due to the impact of (+) ions during the discharge of the plasma display panel, the top dielectric provided in the upper panel is worn out, and at this time, a metallic material such as sodium (Na) may short the electrode.

Therefore, a protective film is formed on the upper plate dielectric provided in the upper panel. The protective film may be formed by coating magnesium oxide (MgO), which withstands the impact of positive ions and has a high secondary electron emission coefficient. By forming the above-mentioned protective film, the driving voltage is lowered, and this lowering voltage can not only reduce power consumption of the plasma display panel but also improve luminance and discharge efficiency.

However, the above-described protective film of the conventional plasma display panel has the following problems.

First, magnesium oxide, which is currently used as a protective film material, does not effectively lower the discharge voltage, which is due to the material properties of magnesium oxide. That is, magnesium oxide has a strong covalent bond structure, and thus can be easily combined with water and impurities such as carbon monoxide. Accordingly, the protective film has a problem in that a small crack is generated on the surface due to the impact of the plasma particles, the service life is reduced, and the number of secondary electrons emitted from the protective film during the counter discharge becomes small.

Second, when the protective film is formed of magnesium oxide, there is a problem in that the jitter property is lowered. In other words, the time that can be allocated to the sustain period within one frame is insufficient in driving the plasma display panel.

For example, if there are 480 scan lines, a scan time of 3 microseconds per line, and a single scan method that scans sequentially from the first scan line to the last scan line at a time, When a frame is driven by dividing into eight subfields, an address period required in one frame takes 480 x 3 micro seconds x 8 = 13 milliseconds or more.

Therefore, since the time that can be allocated to the sustain period in one frame is reduced by that much, it is necessary to reduce the scan period in order to allocate more insufficient sustain period. However, considering the jitter generated during the address discharge, it is difficult to shorten the scan period because the width of the scan pulse must be increased. Jitter is a discharge delay time that occurs during address discharge, but there is a slight difference in every subfield, but it has a certain range during driving. Scan pulses contain these jitter values, which results in longer pulse widths. Therefore, the larger the jitter value, the longer the address period, so that deterioration of image quality may occur.

Here, the factor which has the greatest influence on the jitter value of the address period is the secondary electron emission characteristic of the protective film. That is, the higher the secondary electron emission characteristic of the passivation layer, the smaller the jitter value, and the pulse width of the scan pulse is reduced by the reduced jitter value, thereby shortening the address period.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a plasma display panel having improved jitter characteristics and a method of manufacturing the same.

Another object of the present invention is to provide a plasma display panel and a method of manufacturing the same having improved discharge characteristics and reduced power consumption.

In order to achieve the above object, the present invention is a plasma display panel comprising a first panel and a second panel facing each other with a partition wall therebetween, MgO provided on the first panel, doped with Si A first protective film comprising; And a second protective film provided on the first protective film and including MgO of single crystal.

The second passivation layer may further include a dopant selected from the group consisting of Al, Cr, H ₂ , Si, Sc, and Gd.

According to another embodiment of the present invention, there is provided a method, comprising: forming a first protective film including MgO doped with Si on a dielectric in a first panel; And forming a second passivation film including MgO of single crystal on the first passivation film.

The forming of the first passivation layer may include preparing a first source material including Si-doped MgO and depositing the first source material on the dielectric by an electron beam method.

The forming of the second passivation layer may include preparing a second source material including MgO and depositing the second source material on the first passivation layer by chemical vapor deposition.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

The plasma display panel according to the present invention is characterized in that the protective film is formed in a two-layer structure. Hereinafter, a protective film formed by contacting the dielectric of the upper panel is called a first protective film, and a protective film formed on the first protective film and directly in contact with the discharge space is called a second protective film.

1 is a perspective view showing an embodiment of a protective film structure of a plasma display panel according to the present invention. An embodiment of a protective film of a plasma display panel according to the present invention will be described with reference to FIG. 1.

The first protective film 100a is formed on a dielectric (not shown in the figure). In this case, the first passivation layer includes magnesium oxide 101, and silicon (Si) 102 is included as a dopant. In addition, the first passivation layer may be formed by chemical vapor deposition (CVD), electron beam (E-beam), ion-plating, sol-gel, sputtering, or the like. At this time, when silicon is doped in the first passivation layer, the jitter value of the address period is reduced. However, when the silicon content is larger than a predetermined value, the jitter value may be increased. Therefore, the silicon is preferably doped in a range where the jitter value is minimized, and it is preferable that the silicon is included in the protective film at an optimum content of 20 to 500 parts per million (ppm). And other materials may be used as dopants instead of silicon to reduce jitter. Here, the first protective film is preferably formed to a thickness of 300 ~ 700 nanometers (nm). If the thickness of the first passivation layer is less than 300 nanometers, there is a possibility of false discharge, and if it is more than 700 nanometers, problems in manufacturing process and cost may occur.

Then, a second protective film is formed on the first protective film as shown. The dopant 104 may be doped with the magnesium oxide crystal 103 in the second passivation layer. The second protective film may be formed by chemical vapor deposition, electron beam, sol-gel, ion plating, sputtering, or the like. The size of the magnesium oxide crystals in the second passivation layer may be formed to a size of 500 to 1000 micrometers, and may be formed as a single crystal when formed by chemical vapor deposition. Here, the "size" of a magnesium oxide crystal means the diameter if a crystal is a spherical shape, and the length of one side if it is a hexahedron shape. Single crystal refers to a solid that is regularly produced along a constant crystal axis, and is distinguished from polycrystal, which is a collection of small single crystals with different orientations.

Here, the dopant included in the second protective film is preferably selected from materials consisting of aluminum (Al), chromium (Cr), hydrogen (H ₂ ), silicon (Si), Sc (scandium), and Gd (gadolinium). . In addition, the dopant is preferably contained at a rate of 300 to 1000 ppm. Limiting the proportion of the dopant is the same as the reason for limiting the proportion of silicon in the above first protective film.

The second protective film is preferably formed to a thickness of 100 to 300 nanometers. If the thickness of the protective film is less than 100 nanometers, particles such as magnesium oxide hardly have crystallinity, and if the thickness of the protective film is more than 300 nanometers, problems in manufacturing process and cost may occur.

The manufacturing method of the first protective film and the second protective film and the characteristics of the plasma display panel according to the above will be described later.

2 is a perspective view of a discharge cell structure of an embodiment of a plasma display panel according to the present invention. An embodiment of a plasma display panel according to the present invention will be described with reference to FIG. 2.

In the plasma display panel according to the present exemplary embodiment, the upper panel and the lower panel face each other with partition walls therebetween. On the upper panel, a pair of sustain electrodes formed by pairing a pair of transparent electrodes 80a and 80b and bus electrodes 80a 'and 80b' are arranged on the upper substrate 70 which is a display surface on which an image is displayed. In addition, the lower panel has an address electrode 20 arranged on the lower substrate 10 so as to intersect with the above-described sustain electrode pair, and the lower panel and the upper panel are coupled in parallel at a predetermined distance.

On the lower panel, barrier ribs 40 of stripe type (or well type, etc.) are arranged in parallel to form a plurality of discharge spaces, that is, discharge cells. And, a plurality of address electrodes for generating vacuum ultraviolet rays by performing address discharge are arranged in parallel with the partition wall. On the upper side of the lower panel, red (R), green (G), and blue (B) phosphors 50a, 50b, and 50c, which emit visible light for image display during address discharge, are coated. A lower dielectric layer 30 is formed between the address electrode and the phosphor to protect the address electrode.

The first passivation layer 100a and the second passivation layer 100b are sequentially formed on the upper plate dielectric 90 formed on the pair of sustain electrodes. Specific characteristics of the first passivation layer and the second passivation layer are as described above.

Herein, when discharge occurs in the discharge space, positive ions are generated, but magnesium oxide doped with silicon is formed as the first passivation layer to protect the top dielectric. In addition, the magnesium oxide containing the predetermined dopant may form the second protective film, thereby rapidly reducing the discharge delay time, thereby improving the jitter characteristic. It has been found that the plasma display panel according to the present embodiment shortens the discharge delay time to 1 microsecond or less. In addition, it was found that silicon was included in the first passivation film, thereby improving the secondary electron emission characteristics of the passivation film as a whole.

3 is a flowchart of an embodiment of a method of manufacturing a plasma display panel according to the present invention. An embodiment of a method of manufacturing a plasma display panel according to the present invention will be described with reference to FIG. 3.

First, a first source material that is a first passivation layer material is prepared (S310). Here, the first source material is characterized in that the magnesium oxide contains a small amount of silicon. The first source material may be prepared as a single source material by doping silicon oxide with magnesium, or may be separately prepared.

Next, a first protective film is formed by an electron beam method (S320). That is, the first source material described above is heated to a high temperature to deposit a first passivation layer on the dielectric using physical energy. The first protective film may be formed by a method such as chemical vapor deposition, ion plating, sol-gel, sputtering, etc. in addition to the electron beam method. However, in consideration of the mass productivity and characteristics of the protective film, it is preferable to form the electron beam method. In this case, when the first passivation layer is formed only of magnesium oxide, an aging time is consumed about 9 hours. However, when the first passivation layer is formed using silicon as a dopant, the aging time can be significantly shortened.

In operation S330, a second source material that is a second protective film material is prepared. Here, the second source material is made by doping magnesium oxide with at least one of Al, Cr, H ₂ , Si, Sc and Gd.

Next, a second passivation film is formed by chemical vapor deposition (S340). That is, the second protective film is formed on the first protective film by the steam generated by heating the above-described second source material. At this time, magnesium oxide is deposited in the form of a single crystal and is deposited together with dopants. Here, the chemical vapor deposition method may form the magnesium oxide and the dopants in the second protective film in the physical properties between the film and the crystal, so as to strengthen the deposition strength of the second protective film than when formed by the spray method or the like.

The present invention is not limited to the above-described embodiments, and such modifications are included in the scope of the present invention even if modifications are possible by those skilled in the art to which the present invention pertains.

The effects of the plasma display panel and the manufacturing method according to the present invention described above are as follows.

First, the jitter characteristic of the plasma display panel may be improved.

Second, power consumption may be reduced by lowering the discharge voltage of the plasma display panel.

Claims (10)

In the plasma display panel comprising a first panel and a second panel facing each other with a partition wall therebetween, A first passivation layer provided on the first panel and including MgO doped with Si; And And a second protective film provided on the first protective film and including MgO of single crystal. The method of claim 1, wherein the second protective film, A plasma display panel further comprising a dopant selected from the group consisting of Al, Cr, H ₂ , Si, Sc, and Gd. The method of claim 2, wherein the dopant is And a plasma display panel included in the second passivation layer at a rate of 300 to 1000 ppm. The method of claim 1, wherein the MgO in the second protective film, Plasma display panel, characterized in that the size of 500 ~ 1000 nanometers. The method of claim 1, wherein the first protective film, A plasma display panel formed by an electron beam method. The method of claim 1, wherein the second protective film, A plasma display panel formed by chemical vapor deposition. Forming a first protective film on the dielectric in the first panel, the first protective film comprising MgO doped with Si; And And forming a second protective film containing MgO of single crystal on the first protective film. The method of claim 7, wherein the forming of the first protective film, A method of manufacturing a plasma display panel comprising preparing a first source material including Si-doped MgO and depositing the first source material on the dielectric by an electron beam method. The method of claim 7, wherein the forming of the second protective film, And preparing a second source material including MgO, and depositing the second source material on the first passivation layer by chemical vapor deposition. 10. The method of claim 9, wherein the second source material is A method of manufacturing a plasma display panel further comprising a dopant selected from the group consisting of Al, Cr, H ₂ , Si, Sc, and Gd.

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