KR100443493B1 - Method for forming overcoat layer of ac plasma display panel, including steps of forming dielectric layer through printing, heating dielectric layer, and quickly cooling dielectric layer - Google Patents

Abstract

PURPOSE: A method is provided to efficiently prevent penetration of charged particles by forming an overcoat layer having a micro structure, and achieve improved discharge characteristics by quickly cooling a dielectric layer. CONSTITUTION: A method comprises a step(100) of forming a dielectric layer through a printing method; a step(200) of heating the surface of the dielectric layer by the temperature of 450 to 550 Deg.C through a laser irradiation method; and a step(300) of forming an overcoat layer on the surface of the dielectric layer, by quickly cooling the dielectric layer by performing at least one of the process of injecting gas of 70 to 100 Deg.C, process of leaving the dielectric layer in an ordinary temperature, and the process of spraying water solution of electron emission material to the dielectric layer or dipping the dielectric layer into water solution of electron emission material.

Description

Method for forming protective layer of AC plasma display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of alternating current (AC) type plasma display devices (PDPs), and more particularly to a method of forming a protective layer for protecting a dielectric layer.

The most basic configuration of a PDP that uses gas discharge for image display is a direct current (DC) type PDP, which is an electrode (E1, E2) on two substrates (P1, P2) filled with a discharge gas therebetween in FIG. Has a configuration in which they face each other (B is a bulkhead).

Such DC type PDP is extremely simple in structure and operation, but the discharge start is delayed and discharge occurs only at the time of selection. Therefore, when driving by the general scan method, the duty time is short and the luminous intensity is low. It is difficult to use for moving picture display.

In order to promote the discharge start and maintain the discharge, various types of PDPs have emerged. Among them, an AC type PDP is a typical one, which is formed by stacking a dielectric layer I on one electrode (for example, E2). The wall discharge formed by charging through the dielectric layer I realizes rapid discharge and memory effects.

Each of the functional layers E1, E2, and B, including the dielectric layer I, is configured by printing, which is a thick film method, for cost and convenience of processing. The dielectric layer I is mainly formed by printing and firing particles such as SiO 2 onto a paste. The finished dielectric layer I is relatively large as shown in FIG. 2. And a significant gap is formed between them.

However, since the PDP is a discharge device, there is a problem of sputtering and damaging the electrode E2 (particularly the cathode) through the gap of the dielectric layer I of the charged particles in the discharge space.

Accordingly, an overcoat layer (T) is formed on the dielectric layer (I) by deposition of MgO or the like. The protective layer T made of MgO also serves to lower the discharge start voltage.

However, as the protective layer (T) is formed by a thin film method such as vapor deposition, not only the facility and manufacturing cost of the PDP is greatly increased, but also the MgO protective layer (T) is prone to contamination, requiring a high clean environment and brittleness. There are a variety of problems such as cracks are likely to occur.

In view of such a conventional problem, an object of the present invention is to provide a method for forming a protective layer without depending on the thin film method.

1 is a cross-sectional view showing the basic configuration of an AC PDP.

2 is a partially enlarged cross-sectional view showing the configuration of a protective layer on a dielectric layer.

3 is a flow chart of the method of the present invention.

Figure 4 is a sequential cross-sectional view showing the flow of one embodiment of the present invention accordingly.

5 is a conceptual diagram showing the operation of another embodiment of the present invention.

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

Pl, P2: Substrate

E1, E2: electrode

I: dielectric layer

T: overcoat layer

G: Particles (of the dielectric layer)

G ': microparticles (of protective layer)

M: electron emitting material

Ne: discharge gas

The method according to the present invention for achieving the above object is characterized by forming a medical dielectric layer in a thick film method, heating the surface of the dielectric layer to a high temperature, and then quenching it.

According to another feature of the invention, such quenching is accomplished by cooling the surface of the dielectric layer by spraying or dipping the aqueous solution of the electron-emitting material.

EXAMPLE

Example 1

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

In step 100 of FIG. 3, a dielectric layer I is formed on an electrode (E2 in FIG. 1) by a general thick film method such as printing. Since the dielectric layer (I) is formed by a thick film method, the particle size of the particles (G) is considerably large, and a rough structure is formed in which a gap is formed between the particles (G).

Here, the dielectric layer (I) is mainly composed of SiO ₂ containing a black pigment as a main component, the particles (G) are SiO ₂ particles, pigments or particles such as PbO ₂ , and these particles (G) are mutually by firing A part of the surface is attached.

Next, as shown in FIG. 3 and FIG. 4B, the surface of the dielectric layer I is heated to a predetermined temperature. In this case, the heating temperature is preferably about 450 ° C. to 550 ° C., which is equal to or higher than the recrystallization temperature of SiO ₂ , which is the main component of the dielectric layer (I). .

The preferred method for the surface heating means is irradiation of laser light, and the laser heat source is preferable because it can instantly concentrate high-density energy in a limited area.

Next, the surface of the heated dielectric layer I as shown in FIG. 3 and FIG. 4C is quenched by a predetermined refrigerant A. Referring to FIG.

Then, as shown in FIG. 4D, the particles G around the surface of the dielectric layer I are recrystallized into dense fine particles G ′ to form a dense protective layer T on the dielectric layer I.

The reason why the particles (G) are changed to the fine particles (G ') by surface heating and quenching is because the size of the crystal, that is, the particle size decreases as the cooling rate from the molten state increases. In addition, particles (G) that is recrystallized mainly SiO ₂ particles.

On the other hand, the refrigerant (A) used for quenching after surface heating will be heated to some extent in the case of radiant heat, so if the temperature difference with the refrigerant (A) is too large, the substrate (P1, P2) Damage may occur. Therefore, the refrigerant A is appropriately air or inert gas heated to about 70 to 100 ° C.

On the other hand, when the surface is heated by laser irradiation, the heating range is minutely limited so that it is not transferred to the substrates P1 and P2. In this case, the substrates P1 and P2 may be left at room temperature after heating. No damage occurs and the room temperature itself is quenched.

As described above, according to the present invention, since the protective layer is formed on the surface of the dielectric layer itself, the process is very simple, the process atoms are low, and the requirements for the surrounding environment are also relaxed.

Example 2

On the other hand, a method for implementing another feature of the present invention is also shown in Figure 3 after the formation of the dielectric layer (I in Figure 1) by the thick film process (step 100), after heating the surface of the dielectric layer (I) ( Step 200), it is quenched (step 300) to form a protective layer (T) of dense structure on the surface of the dielectric layer (I).

This method is basically similar to the method of Example 1 described above. According to another feature of the present invention, the quenching process is performed by spraying or dipping the aqueous solution of electron-emitting material.

It can be used as the electron emitting material is preferably a single metal or an oxide thereof of a metal such as Ba, Mg, La or Cr, these are materials that easily emit electrons by the impact of silver or external charge.

When the aqueous solution of the electron-emitting material is sprayed or immersed on the heated dielectric layer (I), the particles (G) on the surface of the dielectric layer (I) are quenched and recrystallized into fine particles, and at the same time, electrons are released in the gaps between the fine particles. Impregnated with aqueous solution of material.

After the dielectric layer (I) is dried, a protective layer (T) is formed on the surface of the dielectric layer (I) made of fine particles in which an electron emission material remains in a gap therebetween.

Here, the electron-emitting material prevents sputtering of the electrode E2 by blocking the gap of the protective layer T, and at the same time, improves discharge characteristics by the same action as in FIG. 5.

In Fig. 5, the discharge gas Ne such as Ne or Ar in the discharge space is ionized and excited by charges charged on the surface of the dielectric layer I (actually the surface of the protective layer T). After first emitting electrons through various mechanisms such as) and penning, the electrons and ions are reacted with charges again to generate a large amount of electrons, that is, discharges.

At this time, the electron-emitting material M impregnated in the protective layer T on the surface of the dielectric layer I is excited by electric charges such as ions and electrons to emit a large amount of secondary electrons.

As a result, the discharge start voltage of the PDP is lowered, which enables rapid discharge start and also improves the discharge strength.

As described above, according to the present invention, a protective layer is formed on the surface of the dielectric layer itself, thereby imparting excellent electrical characteristics, thereby implementing a high linear AC type PDP at low manufacturing cost.

Then, the particles on the surface of the heated dielectric layer are quenched so that the particle size is finely reshaped, that is, recrystallized into fine particles to form a dense structure, thereby effectively preventing the penetration of charged particles. At the same time, the electron-emitting material is impregnated into the gap between the fine particles, thereby improving discharge characteristics such as secondary tank emission.

Claims (2)

In the method of forming a protective layer on the dielectric layer of the alternating plasma, The dielectric layer is formed by a thick film method, After heating the surface of the dielectric layer to a predetermined temperature of 450 ℃ to 550 ℃ by laser irradiation, At least one of the step of quenching by gas injection at 70 to 100 ° C., quenching by standing at room temperature, and quenching by spraying or immersing an aqueous solution of electron-emitting material on the dielectric layer to form a dense surface of the dielectric layer. A protective layer forming method for an alternating current plasma display device, characterized by forming a protective layer having a structure. The method of claim 1, wherein when the quenching step is a quenching step by spraying or immersing an aqueous solution of the electron-emitting material on the dielectric layer, the electron-emitting material is at least one of Ba, Mg, La, or Cr, or an oxide thereof. A protective layer forming method for an alternating current plasma display device, characterized in that.

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