KR100517967B1 - Plasma display panel and manufacturing method thereof - Google Patents

Abstract

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 and a method of manufacturing the same, which can improve adhesion between a dielectric layer for a PDP top plate and a magnesium oxide (MgO) protective film prepared in a liquid phase. Conventional magnesium oxide protective film formation using the liquid magnesium oxide has a weak adhesive strength of the formed magnesium oxide protective film and the upper dielectric layer. In view of the above problems, the present invention forms an amorphous matrix layer by adding an inorganic binder (Mg-O- structure) to the liquid magnesium oxide protective film, or is formed by mixing the upper dielectric layer glass powder with magnesium oxide powder, or By directly dissolving magnesium oxide powder in the dielectric layer, the adhesion between the upper dielectric layer and the magnesium oxide protective film can be improved. In addition, since the present invention uses magnesium oxide powder having excellent crystallinity, it is possible to increase the secondary electron emission coefficient, thereby lowering the starting and holding voltages and increasing the lifespan.

Description

Plasma display panel and its manufacturing method {PLASMA DISPLAY PANEL AND MANUFACTURING METHOD THEREOF}

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 and a method of manufacturing the same, which can improve adhesion between a dielectric layer for a PDP top plate and a magnesium oxide (MgO) protective film prepared in a liquid phase.

As the development and spread of information processing systems increase, the importance of display devices as visual information transmission means is increasing. In particular, the conventional CRT (Cathod Ray Tube) has various problems such as large size, high operating voltage, and display distortion, so that the recent trend of increasing screen size and flatness is not suitable. Research of flat panel displays is actively underway.

A typical plasma display panel (PDP) is a device that displays images containing characters or graphics by emitting phosphors by 147 nm ultraviolet rays generated when the He + Xe or Ne + Xe inert mixed gas is discharged. Rather, the display quality is excellent and the response speed is fast. In addition, since it can be thinned, it is also attracting attention as a wall-mounted display with a liquid crystal display (LCD).

PDPs are classified into a surface discharge type and an opposite type according to the arrangement of the electrodes, and are classified into an AC discharge type, an AC discharge type, a DC discharge type, or a hybrid type according to whether the electrode is exposed. The three-electrode AC surface discharge type PDP has advantages of low voltage driving and long life because wall charges are accumulated on the surface during discharge and protect the electrodes from sputtering caused by the discharge.

1 is a cross-sectional view of a typical AC surface discharge plasma display panel. As shown, the lower substrate 1, the address electrode 2 formed on the lower substrate 1, the lower dielectric layer 3 formed on the address electrode 2, and the lower dielectric layer 3 It is formed on the top to maintain a discharge distance, to prevent the electro-optic crosstalk between the cells and includes a partition wall (4) for receiving the phosphor layer (5).

In addition, a protective film 6 is formed on the upper dielectric layer 7, which protects the sputtering of the upper dielectric layer 7 by gas ions during discharge, thereby increasing the service life and increasing the discharge start voltage by secondary electron emission. The lower the discharge start voltage, not only to obtain a stable discharge but also to increase the life of the electrode. The space between the protective film 6 and the phosphor layer 5 is filled with an inert gas such as Ne + Xe, He + Xe.

In addition, a discharge holding electrode 8 consisting of two electrodes is formed on the upper substrate 9 of the PDP, and the discharge holding electrode 8 is a transparent electrode 8a so as not to inhibit light transmission of the upper substrate 9. 8b) and an indium-tin-oxide (ITO) electrode. In order to prevent the voltage drop of the discharge holding electrode 8, bus electrodes 8'a and 8'b, which are metal electrodes having a smaller area, are provided.

The upper dielectric layer 7 is formed on the discharge sustaining electrode 8, which limits the plasma discharge current and accumulates wall charges during discharge.

Then, referring to Figure 1 will be described the operation principle of the PDP. First, a voltage corresponding to the discharge sustain voltage is applied between the two electrodes 8a and 8b constituting the discharge sustain electrode 8 to accumulate charge in the upper dielectric layer 7.

Subsequently, when a voltage corresponding to the discharge start voltage is applied to the address electrode 2, an inert gas is separated into electrons and ions by a glow discharge, and the plasma is formed, and the phosphor is emitted by ultraviolet rays generated at the moment when the electrons and ions are recombined. The layer 5 develops.

The manufacturing process of such a PDP will be described with reference to the block diagram shown in FIG.

2 shows a manufacturing process of the upper substrate 9 of the conventional PDP. As shown, processing the glass, which is the upper substrate 9, forming the discharge holding electrode 8 on the upper substrate 9, and forming an upper dielectric layer on the discharge holding electrode 8; 7) and sealing on the upper dielectric layer 7 and forming a protective film (6).

The discharge sustaining electrode 8 includes forming two electrodes 8a and 8b as transparent electrodes on the upper substrate 9 and a bus electrode as an auxiliary electrode on a portion of the formed two electrodes 8a and 8b. 8'a, 8'b).

Referring to the manufacturing process of the upper substrate (9) consisting of these steps, the transparent electrode (8a, 8b) is formed on the upper substrate 9 by a method such as sputtering or vacuum deposition, the transparent Bus electrodes 8'a and 8'b made of Cr / Cu / Cr are formed on the electrodes 8a and 8b by sputtering.

The upper dielectric layer 7 formed on the discharge holding electrode 8 formed of the transparent electrodes 8a and 8b and the bus electrodes 8'a and 8'b is applied by a screen printing method, and the upper dielectric layer 7 Seal on).

A protective film 6 is then formed on the upper dielectric layer 7 surface, which is usually made of magnesium oxide (MgO), which is about 500 nm using E-beam or liquid magnesium oxide. It deposits about (5000 Pa).

However, the formation of the protective film using the conventional liquid magnesium oxide as described above has a weak adhesive strength between the formed magnesium oxide protective film and the upper dielectric layer.

Therefore, in view of the above problems, the present invention adds an inorganic binder (Mg-O- structure) to the liquid magnesium oxide protective film to form an amorphous matrix layer, or is formed by mixing the upper dielectric layer glass powder with magnesium oxide powder or It is an object of the present invention to provide a plasma display panel and a method of manufacturing the same, which can improve the adhesion between the upper dielectric layer and the magnesium oxide protective film by directly dissolving magnesium oxide powder in the upper dielectric layer.

In addition, an object of the present invention is to provide a plasma display panel and a method for manufacturing the same, which can increase the secondary electron emission coefficient and lower the start-up and holding voltage and increase the lifespan by using magnesium oxide powder having excellent crystallinity. .

Plasma display panel of the present invention for achieving the above object is in the plasma display panel forming a liquid magnesium oxide (MgO) protective film on the upper dielectric layer, the inorganic binder (Mg-O- structure) is added to the magnesium oxide powder It is characterized by including a magnesium oxide protective film formed of a matrix layer.

In the plasma display panel of the present invention for achieving the above object, in the plasma display panel forming a liquid magnesium oxide (MgO) protective film on the upper dielectric layer, the glass powder for the upper dielectric layer is mixed with magnesium oxide powder in a predetermined ratio. Characterized in that it comprises a magnesium oxide protective film formed.

In addition, the ratio of the glass powder for the upper dielectric layer mixed with the magnesium oxide powder is characterized in that less than 10wt% (wt%).

In the plasma display panel of the present invention for achieving the above object, in the plasma display panel forming a liquid magnesium oxide (MgO) protective film on the upper dielectric layer, the magnesium oxide powder directly melted on the upper dielectric layer (melt-in) Characterized in that it comprises a magnesium oxide protective film formed.

The present invention provides a plasma display panel manufacturing method for forming the discharge sustaining electrode (transparent electrode + bus electrode) and the upper dielectric layer on the upper substrate, drying the upper dielectric layer, and the upper dielectric layer Coating and drying the liquid magnesium oxide (MgO) protective film having enhanced adhesion to the; and sintering the upper dielectric layer and the magnesium oxide protective film at the same time.

In addition, the liquid magnesium oxide protective film is formed of a matrix layer in which an inorganic binder (Mg-O- structure) is added to magnesium oxide powder, or a predetermined ratio (10% or less) of the upper dielectric layer glass powder is mixed with magnesium oxide powder. Or magnesium oxide powder is directly dissolved in the upper dielectric layer.

The liquid magnesium oxide protective film may be formed by milling a mixture of nanopowdered magnesium oxide with a solvent and a polymer dispersant using a milling machine and coating the upper dielectric layer.

The method may further include drying the upper dielectric layer and semi-firing at a predetermined temperature (350 ° C.).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a plasma display panel of the present invention having a feature as described above and a method of manufacturing the same will be described with reference to the accompanying drawings.

FIG. 3 illustrates a manufacturing process up to forming a protective film on an upper substrate in the plasma display panel of the present invention. As shown, processing the upper substrate (eg, glass), and sequentially depositing two electrodes as transparent electrodes on the upper substrate and a bus electrode as an auxiliary electrode on a portion of the two electrodes to maintain discharge Forming an electrode, forming an upper dielectric layer on the discharge sustaining electrode, drying the formed upper dielectric layer, coating and drying liquid magnesium oxide (MgO) on the dried upper dielectric layer; And simultaneously firing the dried upper dielectric layer and the magnesium oxide protective film.

FIG. 4 illustrates another embodiment of a manufacturing process up to forming a protective film on an upper substrate in the plasma display panel of the present invention. As illustrated, the method further includes forming and drying the upper dielectric layer in the manufacturing process illustrated in FIG. 3 and then semi-firing the dried upper dielectric layer at a predetermined temperature (about 350 ° C.).

3 and 4, when the upper dielectric layer and the lower dielectric layer are fired twice, the lower dielectric layer performs both drying and firing processes, and only the upper dielectric layer is dried, and then liquid phase oxidation. Magnesium protective coating.

In addition, in the present invention, the liquid magnesium oxide is coated on the upper dielectric layer, and a sealing process is performed on the lower substrate instead of the upper substrate to adsorb the upper substrate and the lower substrate in order to perform a drying / firing process.

Then, the present invention consisting of these steps will be described. First, a transparent electrode is formed on the upper substrate by a method such as sputtering or vacuum deposition, and a bus electrode made of Cr / Cu / Cr is formed on the transparent electrode by a sputtering method.

An upper dielectric layer is formed on the discharge sustaining electrode formed of the transparent electrode and the bus electrode by using a screen printing method, and the formed upper dielectric layer is dried. In this case, when the upper dielectric layer is formed of two layers, an upper dielectric layer and a lower dielectric layer, a lower dielectric layer is formed to perform a drying / firing process, and then an upper dielectric layer is formed to perform only a drying process. In addition, a process of semi-baking the dried upper dielectric layer at a predetermined temperature (350 ° C.) may be performed.

A liquid magnesium oxide protective film is coated on the formed upper dielectric layer, and the coated magnesium oxide protective film is dried.

Then, the dried upper dielectric layer and the magnesium oxide protective film are fired at the same time to complete the formation of the upper dielectric layer and the magnesium oxide protective film.

Here, an exemplary method of manufacturing liquid magnesium oxide for improving adhesion between the upper dielectric layer and the magnesium oxide protective film and forming the protective film is illustrated in FIGS. 5 to 8.

Figure 5 illustrates a process of forming a liquid magnesium oxide using nano-powder magnesium oxide applied to the present invention. As shown, a solvent, a polymer dispersant, and nano powdered magnesium oxide are mixed (pre-mixed), and the mixture is milled using a milling machine and coated on the upper dielectric layer to form a liquid magnesium oxide protective film.

At this time, the mixture is a uniform size of magnesium oxide powder of a predetermined size (for example 50nm) or less by 1 to 20wt% (weight%, weight percent), solvent and polymer propellant by 0.5 to 10wt% Is formed.

In addition, the mixture of the solvent, the polymer dispersant, and the nano-powder magnesium oxide in a predetermined ratio is formed through stirring for a predetermined time (1 hour) and ultrasonic dispersion using an ultrasonic disperser.

The resulting mixture is milled using a milling machine, screen printing, dipping, die coating, spin coating, green sheet coating, inkjet It is formed by coating on the upper dielectric layer using a coating method such as (ink-jet). Here, the ratio of the liquid magnesium oxide formed through the process is different depending on the coating method, for example, 2wt% or less in the case of die coating and dipping, 10wt% in the case of inkjet and green sheet coating and spin coating In the case of 10 ~ 20wt% is suitable.

When the liquid magnesium oxide protective film formed by this process passes through the manufacturing process of FIG. 3 or 4, the adhesion between the upper dielectric layer and the magnesium oxide protective film may be enhanced.

6 is another method for enhancing the adhesion between the upper dielectric layer 7 and the magnesium oxide protective film 6, a method of forming a protective film using a film forming agent having a material similar to that of magnesium oxide and at the same time strengthening the adhesive force. to be. For example, a binder containing a magnesium-oxygen (Mg-O-) structure is mixed with magnesium oxide powder, a solvent, and a dispersant to form liquid magnesium oxide, and the liquid magnesium oxide thus formed is coated on the upper dielectric layer 7. When dried / baked, oxygen is removed and the binder becomes an amorphous (mamorphous) inorganic binder. Here, the film forming agent is excellent in viscosity and becomes a transparent film after firing. Therefore, the strength of the magnesium oxide protective film 6 can be increased and the adhesion to the dielectric can be enhanced.

Fig. 7 also shows another method for enhancing the adhesion between the upper dielectric layer 7 and the magnesium oxide protective film 6, wherein the magnesium oxide (MgO) powder is 10 wt% (weight percent) of the glass powder used for the upper dielectric layer 7. By mixing below to form a liquid magnesium oxide, it is possible to enhance the adhesion between the upper dielectric layer 7 and the magnesium oxide protective film (6).

For example, the magnesium oxide powder is mixed with the glass powder for the upper dielectric layer (eg, Non-PbO glass powder) of 10 wt% or less with a solvent and a dispersant to form liquid magnesium oxide, and the formed liquid magnesium oxide is added to the upper dielectric layer. (7) When it is coated on the top and dried / baked, the glass powder contained in the liquid magnesium oxide penetrates into the upper dielectric layer 7, and some may remain in the magnesium oxide protective film to enhance adhesion.

FIG. 8 also shows another method of enhancing adhesion between the upper dielectric layer 7 and the magnesium oxide protective film, in which magnesium oxide powder is directly melted in the upper dielectric layer 7 (melt-in), and the protective film is formed of liquid magnesium oxide thereon. It can be formed to strengthen the adhesion between the upper dielectric layer 7 and the magnesium oxide protective film. That is, magnesium oxide (MgO) in powder form is directly melted on the upper dielectric layer 7, and the liquid magnesium oxide is applied to a predetermined thickness thereon, and then dried / baked to the magnesium oxide powder dissolved in the upper dielectric layer 7. By this, the adhesive force can be strengthened.

6 to 8 are not only the manufacturing method according to FIGS. 3 and 4, but also the prior art method of drying / firing an upper dielectric, coating liquid magnesium oxide, and drying / firing a magnesium oxide protective film. It is also applicable to the process of forming a.

As described in detail above, the present invention is formed by adding an inorganic binder (Mg-O- structure) to the liquid magnesium oxide protective film to form an amorphous matrix layer, or by mixing glass oxide powder for the upper dielectric layer with magnesium oxide powder, By directly melting and forming magnesium oxide powder in the upper dielectric layer, the adhesion between the upper dielectric layer and the magnesium oxide protective film can be improved.

In addition, since the present invention uses magnesium oxide powder having excellent crystallinity, it is possible to increase the secondary electron emission coefficient, thereby lowering the starting and holding voltages and increasing the lifespan.

1 is a cross-sectional view of a typical AC surface discharge plasma display panel.

2 is a flowchart of a manufacturing process on a conventional plasma display panel upper substrate.

3 is a flowchart of a manufacturing process on the upper substrate of the present invention plasma display panel.

Figure 4 is another flow chart of the manufacturing process on the upper substrate of the plasma display panel of the present invention.

Figure 5 is a flow chart showing an embodiment process of forming a liquid magnesium oxide protective film in the present invention.

Figure 6 is an embodiment for enhancing the adhesion of the upper dielectric layer and the protective film in the present invention.

Figure 7 is another embodiment for enhancing the adhesion of the upper dielectric layer and the protective film in the present invention.

Figure 8 is another embodiment for enhancing the adhesion of the upper dielectric layer and the protective film in the present invention.

Claims (8)

delete In the plasma display panel forming a liquid magnesium oxide (MgO) protective film on the upper dielectric layer, And a magnesium oxide protective film formed by mixing the magnesium oxide powder with the glass powder for the upper dielectric layer in an amount of 10 wt% or less (weight percent) or less. delete In the plasma display panel forming a liquid magnesium oxide (MgO) protective film on the upper dielectric layer, And a magnesium oxide protective film formed by melting magnesium oxide powder directly on the upper dielectric layer. Forming a discharge holding electrode (transparent electrode + bus electrode) and an upper dielectric layer on the upper substrate, and drying the upper dielectric layer; Magnesium oxide powder is formed on top of the upper dielectric layer by mixing the glass powder for the upper dielectric layer of 10% or less, or magnesium oxide powder is formed by melting directly on the upper dielectric layer to form a liquid magnesium oxide (MgO) protective film to enhance adhesion. Coating and drying; And firing the upper dielectric layer and the magnesium oxide protective film at the same time. delete The method of claim 5, wherein the liquid magnesium oxide protective film is formed by milling a mixture of nano-powdered magnesium oxide with a solvent and a polymer dispersant using a milling machine and coating the upper dielectric layer. . The method of claim 5, further comprising drying the upper dielectric layer and semi-firing at a temperature of 350 ° C.