KR100424301B1 - The manufacturing method of Plasma Display Panel - Google Patents

Abstract

The present invention relates to a PDP manufacturing method in which a plurality of microtubes are installed in a coating path of a real material in order to make the discharge gas pressure inside the PDP cell equal to the process pressure, thereby preventing the discharge voltage from increasing. A first step of loading and cleaning the inside of the plasma chamber, and in order to make the discharge gas pressure inside the PDP cell equal to the process pressure in the chamber, a plurality of microtubes are formed to penetrate the bottom substrate of the loaded panel. A second step of mounting and applying the actual material, a third step of evacuating the inside of the plasma chamber and injecting a discharge gas, and a fourth step of bringing the upper and lower substrates together by aligning the lower and upper substrates; And a fifth step of removing the microtube when the pressure of the plasma chamber and the pressure inside the panel match. After curing made of a sixth step of unloading a panel from a plasma chamber, to avoid the increase of the discharge voltage generated from the actual process it is advantageous to improve the durability and reliability of the product.

Description

PD manufacturing method {The manufacturing method of Plasma Display Panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a PDP, which is one of the new image display apparatuses in the multimedia era. The present invention relates to a PDP manufacturing method for producing a PDP with a discharge voltage.

In the current era of multimedia, display devices that can express colors more finely, larger, and closer to natural colors are required. However, there is a limit to the current CRT (Cathode Ray Tube) structure or LCD (Liquid Crystal Display) method to form a large screen of 40 inches or more. Accordingly, many questions have been derived from the question "What is the next-generation display device?", And PDP (Plasma Display Panel) is also one of the answers.

As shown in FIGS. 1 and 2, the PDP is a display device which is completed by coating several films required on two flat glasses forming the upper substrate 10 and the lower substrate 20 and then attaching them to each other.

The PDP is manufactured by attaching the lower substrate 20 and the upper substrate 10. After the address electrode 22 is provided on the flat glass 21, the dielectric film 23 is formed, and the partition wall 24 is formed to distinguish each cell, and then the dielectric film 23 and the partition wall 24 are surrounded. Phosphor 25 is applied to the bottom substrate 20, and the auxiliary electrode 12 and the transparent electrode 13 are provided below the other flat glass 11, and then the dielectric film 14 is formed. After the upper substrate 10 is completed by forming a protective film 15 below the upper substrate 10, the upper substrate 10 and the lower substrate 20 are attached to each other with a small gap to complete the manufacture of the PDP. Of course, a discharge gas that is an inert gas must be inserted between the upper and lower substrates 10 and 20.

The operation principle of the PDP configured as described above is as follows.

When electric energy is applied to discharge gas discharged between the substrates 10 and 20 to discharge, ultraviolet rays are emitted. The ultraviolet rays of the specific wavelength band emit visible phosphors by emitting the phosphor 25 of the substrate 20. Will be able to see the image on the screen. Since the inert gas discharges inside the panel formed by the upper substrate 10 and the lower substrate 20, the films coated on the inside of the panel should be firmly made, and other impurities other than the inert gas may not enter or be generated during discharge. It should not be. This depends on product performance and lifetime.

Here, the manufacturing process of the PDP can be classified into a front process, a post process, and a module process. In the previous process, various films required for flat glass can be coated to manufacture the upper and lower substrates.The latter process is the bonding of the upper and lower substrates, exhaust, discharge gas injection and tip off, aging, and inspection steps. Consists of In addition, the module process is a final process of completing the PDP, and is composed of the steps of mounting and assembling a circuit.

The previous step is a step of manufacturing the upper and lower substrates as described above, the finished upper and lower substrates are put into the later process. The purpose of the post process is to attach the upper and lower substrates, and to remove contaminants from the upper and lower substrates. In addition, one of the objectives is to finally confirm whether the PDP can achieve satisfactory performance and function, and the inspection is performed after the discharge gas is injected and aged.

The first step of the post process is a process of bonding the upper substrate 10 and the lower substrate 20 as shown in FIGS. 3 and 4. After applying a seal to the upper substrate 10, the lower substrate 20 is approached and fixed, and then the melts are melted at a high temperature to be bonded to each other. The main component of the material used for bonding the substrate is frit (glass, SiO ₂ ), and some additives are mixed in order to improve applicability and adhesion.

Looking at the bonding method in detail as follows. Using a dispenser, the frit seal 30 is applied to the edge of the upper substrate 10 to a predetermined thickness and then dried at a temperature of about 120 ° C. Then, plasticity is performed at a temperature of 400 ° C. or higher in order to remove impurities remaining in the real material, and then the upper and lower substrates 10 and 20 are aligned and fixed to the bonding forceps 35. Thereafter, the frit seal 30 is melted at a temperature equal to or higher than the melting point of the actual material so that the upper substrate 10 and the lower substrate 20 are bonded together.

The second step of the post process is to remove impurities attached to various films formed on the upper substrate 10 and the rear substrate 20 and the impurity gas from the membrane. Removal of impurities and impurity gases is achieved through high vacuum and exhaust repetition. That is, as shown in FIG. 3, when the upper substrate 10 and the lower substrate 20 are attached to each other, an exhaust pipe 40 is installed and a vacuum or exhaust is performed through the exhaust pipe 40. The exhaust pipe 40 generally uses a long cylindrical glass tube, which is also called a tip, and is installed on the lower substrate 20 using a frit ring 31 when the substrate is bonded. That is, an exhaust hole 27 is formed in the lower substrate 20, the exhaust pipes 40 are aligned with the exhaust hole 27, and the frit ring 31 is melted and solidified to complete the installation.

The final stage of the post process is the process of injecting, aging, and discharging the discharge gas. Discharge gas is injected through the exhaust pipe 40, and heat is melted and sealed at the end of the exhaust pipe 40 so that the injected discharge gas does not leak. This process is called tip-off, and aging and inspection are performed after the tip-off.

Subsequent substrate bonding, evacuation, gas injection and tip off may be performed in the same facility, or substrate bonding may be in a separate facility and the remainder in the same facility. The former is called integral and the latter is called discrete.

Thus, in the case of the type with the exhaust pipe 40, since the exhaust time takes a lot, when the production equipment is equipped, the length of the equipment becomes more than a few tens of meters and occupies a lot of space. In addition, dozens of carts are required to load several PDPs, pass through a hot blast furnace, and unload the panels. The cart has a very complicated structure, such as a pump for vacuum, a vacuum piping system, a cylinder and piping system for gas injection, and a tip off unit.

This process is currently widely used, but there are some problems. First, it takes a lot of time to exhaust with a high vacuum. When the 40-inch upper surface of the substrate there the substrate is placed cementation / sealing of several hundred micrometer gap the impurity gas trapped in the gap, because exhaust through the narrow exhaust tube 40 in a corner, a high vacuum (10 ^{- 7} Torr) takes hours. Because of the high heat applied to this enormous high vacuum, the panel is subjected to enormous load, and since PDP is inherently vulnerable to thermal variation and tensile strength, the ambient conditions applied can adversely affect the PDP properties. Therefore, there is a need for a method that can easily exhaust or clean at low temperatures and atmospheric pressures and reduce the exhaust time.

In addition, the exhaust pipe 40 attached to the PDP breaks well during the movement of the panel or during exhaust or gas injection. Since the exhaust pipe 40 is also a glass tube, the exhaust pipe 40 may be damaged due to a shock during movement, or a heat deviation during exhaust and temperature increase during exhaust. In addition, even when tip off after gas injection, automation is difficult due to the structure of the thin and long exhaust pipe 40 and the glass being vulnerable to impact. As a result, if the tip has a long exhaust time, it becomes a bottleneck for the entire production process, and requires a large amount of equipment space for mass production. Therefore, how to quickly and cleanly remove the contaminants generated from the upper substrate 10 and the lower substrate 20 remains a homework. That is, it is possible to reduce the exhaust time and eliminate the damage of the exhaust pipe 40, and it is the most important and urgent task to clean the contaminated material of the upper substrate 10 and the lower substrate 20 in a short time.

In addition, the frit glass generally used in the plastic is plasticized at a high temperature of 400 ° C. or higher to remove impurities, but when it is bonded, a large amount of impurities are generated when melting at the melting point temperature of the frit glass. It takes a lot of time to be sucked into the PDP cell and exhausted. In addition, the plasticity of the material at a high temperature of 400 ℃ or more and the process time is long by melting the material, the energy consumption due to heating and cooling is high, and the material is good rigidity and adhesive strength, but weak to external impact, causing cracks due to impact. do.

Various methods have been devised to solve the problems of the above-described technology, and one of them is to exhaust the exhaust gas first and later to bond the substrate and inject gas in order to improve the exhaust method and fundamentally eliminate the damage of the exhaust pipe.

That is, in the case where the exhaust pipe is provided, the work proceeds through the processes of coalescing, exhaust and gas injection, and tip-off, but exhausting is performed first and then coalescing later so that the exhaust pipe is not required. However, in this method, when the frit seal is melted to bond the two substrates after exhausting, a large amount of impurity gas is released to contaminate the inside of the PDP cell, and the expensive discharge gas is caused by the impurity gas when it is bonded in the discharge gas atmosphere. It is contaminated and has a problem such that it cannot be used.

In order to prevent contamination of the discharge gas, a semi-tip-less method of injecting the discharge gas through a separate hole without filling the chamber has also been devised. However, the semi-tipless method also melts the frit seal after discharging the gas and seals the injection hole, which is hardly put to practical use due to a fatal defect in which impurity gas generated during melting enters into the PDP cell.

That is, in the tipless or semi-tipless method, the frit seal is melted and attached at a high temperature. When the frit seal melts, a large amount of impurities are generated. When the impurity gas flows into the inside of the PDP cell, the quality of the PDP is deteriorated, which makes it difficult to use. Therefore, at present, a type having an exhaust pipe is mainly used, and a tipless method and a semi-tipless method are rarely used due to the above problems.

However, the current exhaust and gas injection process is exposed to the atmosphere for a predetermined time after forming a protective film of the upper substrate, and then adhered to the exhaust and gas injection process. Magnesium oxide (MgO) is mainly used as a protective film, and magnesium oxide has a property of binding well with various components such as moisture contained in the atmosphere when exposed to the atmosphere. These components lead to longer exhaust times, lower protective film quality, adversely affect product performance and shorten product life.

In order to solve these problems, a process system for exhaust and discharge gas injection and coalescence using UV materials has been developed. This system places a cleaned substrate inside the plasma chamber, so that the substrate is not exposed to the atmosphere. In this state, the inside of the plasma chamber is maintained in a vacuum, and an epoxy-based substance is applied inside the plasma chamber in which the dispenser unit is mounted. If the chamber is evacuated to 10 ^-5 Torr or less in the state in which the substance is applied, the boiling point of the solvent dissolved in the substance is lowered and the volatile component of the solvent is released from the substance. At this time, since the vacuum pump is connected to the plasma chamber and the vacuum is being exhausted, volatile components of the solvent are also exhausted through the vacuum pump.

In this way, the discharge gas is injected to the process pressure into the plasma chamber exhausted in a high vacuum state. When the discharge gas is injected into the plasma chamber to the desired pressure, the upper and lower substrates are identified by raising the lower substrate through a stage unit which raises or lowers the lower substrate so that alignment marks can be identified by a CCD camera or visually. Align it. Here, a spring is provided in the pin portion of the stage unit so that the upper substrate is not damaged by the pushing force when the lower substrate is pushed up.

When the upper substrate and the lower substrate are in close contact with each other, the substance dispensed on the lower substrate is spread widely. In this state, the upper substrate and the lower substrate are bonded by irradiating UV through the sight window installed in the plasma chamber to complete the process.

The process system using the above-mentioned UV substance has a problem to be improved for the following reasons. When looking at the process flow, first, after dispensing the material, the discharge gas is put into the bonding chamber at a desired pressure, and then the upper and lower substrates are aligned, and the lower substrate is moved to the upper substrate side and bonded. After the upper and lower substrates are bonded together, UV is hardened by irradiation with UV.

By the way, the height of the dispensed reality is determined by the properties of the dispensing unit and the reality. That is, the height and width are determined by the viscosity, the dispensing speed and the amount of the substance. On the other hand, the spacing between the upper and lower plates of a general PDP is determined by the height of ribs formed on the lower substrate, and in order to achieve bonding, the height of the dispensed material must be dispensed higher than the height of the ribs. After dispensing the material, the upper and lower substrates approach the upper substrate, and the upper substrate comes into contact with the actual material applied to the lower substrate. It is to let.

Here, the pressure in the PDP cell at the instant when the upper substrate touches the material applied to the lower substrate is equal to the pressure of the discharge gas injected into the bonding chamber. However, the pressure in the cell is increased while the substance spreads to the same height as the ribs of the lower surface of the PDP. That is, the amount of discharge gas inside the PDP cell is constant from the moment when the upper substrate touches the reality, but the volume of the discharge gas decreases as the upper substrate approaches the lower substrate, thereby increasing the pressure inside the PDP cell. As such, the pressure inside the PDP cell is increased compared to the pressure inside the coalescing chamber, which means that the voltage is relatively higher than the original expected discharge voltage. As a result, this part remains a problem in the actual PDP manufacturing process.

However, in consideration of the pressure of the discharge gas increased inside the PDP cell, the pressure of the discharge gas supplied into the coalescing chamber cannot be lowered. This is because the application of the actual material is not always made at a constant height, and the pressure of the discharge gas supplied into the bonding chamber cannot be set by accurately calculating the volume change.

In other words, in the conventional PDP manufacturing method, when the upper substrate and the lower substrate are bonded together, the pressure inside the PDP cell becomes larger than the expected pressure, thereby requiring a relatively high discharge voltage.

The present invention has been made to solve the above problems of the prior art, in order to prevent the discharge voltage is increased by installing a plurality of micro-tubes in the coating path of the real in order to make the discharge gas pressure inside the PDP cell equal to the process pressure. The purpose of the present invention is to provide a PDP manufacturing method.

1 is a perspective view of a PDP in a multi-layered structure;

2 is a cross-sectional view showing a basic cell structure of a PDP;

Figure 3 is a cross-sectional view showing the exhaust pipe installation portion in the conventional PDP manufacturing process.

4 is a reference diagram showing the bonding process of the substrate in the conventional PDP manufacturing process,

5 is a process diagram illustrating a PDP manufacturing method according to the present invention;

6A to 6D are views illustrating a process of installing and removing a micro tube, which is a main component of the present invention.

<Explanation of symbols on main parts of the drawings>

50: lower surface substrate 51: real

52: micro tube 60: top substrate

In order to solve the above technical problem, the present invention provides a first step of loading and cleaning a panel into a plasma chamber, and in order to make the discharge gas pressure inside the PDP cell equal to the process pressure in the chamber, the lower substrate of the loaded panel A second step of mounting the plurality of microtubes to penetrate the actual material and applying the actual material, a third step of evacuating the inside of the plasma chamber and injecting discharge gas, and raising the lower substrate A fourth step of bonding the upper and lower substrates to each other; and a fifth step of removing the microtubes when the pressure of the plasma chamber and the pressure inside the panel match; and unloading the panel from the plasma chamber after curing the material. It is characterized by consisting of a sixth step.

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

In the PDP manufacturing method according to the present invention, as shown in FIGS. 5 and 6, a first step of loading and cleaning a panel into a plasma chamber, and mounting a microtube 52 on a bottom substrate 50 of the loaded panel And a third step of applying the material 51, a third step of evacuating the inside of the plasma chamber, and then injecting discharge gas, and raising the lower substrate 50 while aligning the upper substrate 60 and the lower substrate. A fourth step of attaching the 50 to the first step; and a fifth step of removing the microtubes 52 when the pressure in the plasma chamber and the pressure inside the panel coincide; and curing the material 51 and then removing the panel from the plasma chamber. It consists of a sixth step of unloading.

Here, in the first step, after the panel is loaded into the plasma chamber, the inside of the chamber is evacuated to a predetermined degree of vacuum, the cleaning gas is injected, and after the plasma is applied, the evacuation is performed again. This first step, the third step and the fourth step go through the same process as in the prior art.

In the second step, a plurality of microtubes 52 are installed so as to penetrate the material 51 at the position where the material 51 is applied, and the actual material 51 is applied thereon to a required height through several repetitions. Allow to be applied. In the fifth step, the microtubes 52 are removed in a state where the internal and external pressures of the panel are matched, and the fluid 51 actually fills a position where the microtubes 52 exit.

In the PDP manufacturing method configured as described above, the inside of the panel is matched to the process pressure by using a micro tube to prevent the pressure increase inside the PDP cell.

The panel consisting of the upper substrate 60 and the lower substrate 50 is loaded into the plasma chamber and the loading gate of the chamber is closed. In this state, the inside of the plasma chamber is evacuated to a vacuum of 10 ⁻⁷ Torr, a cleaning gas of 500 mTorr or less is injected, and plasma is applied to clean the panel. Subsequently, vacuum cleaning is performed using nitrogen gas, which is the same as a general PDP manufacturing method.

Thereafter, a plurality of microtubes 52 are installed on the lower substrate 50. The micro tube 51 is installed to penetrate the actual material 51 applied to the lower substrate 50, as shown in Figure 6a, evenly installed in all directions and the diameter does not exceed the rib height of the lower substrate 50 It is desirable to have. When the micro tube 52 is installed, the material 51 is applied to the lower surface substrate 50, and the actual material 51 is applied to a position relatively higher than the rib of the lower surface substrate 50 as shown in FIG. 6B. It is natural.

When the application of the material 51 is completed, the inside of the plasma chamber is evacuated and the discharge gas is injected in the same manner as in the conventional method. When the injection of the discharge gas is completed, the lower substrate 50 is raised to align with the upper substrate 60. When the alignment of the lower surface substrate 50 is completed, the lower surface substrate 50 is further raised so that the real material 51 contacts the upper surface substrate 60. Subsequently, the lower substrate 50 is continuously raised so that the height of the real material 51 is about the height of the ribs as shown in FIG. 6C to complete the bonding of the substrate.

When the bonding of the substrate is completed, the pressure inside the PDP cell increases with respect to the process pressure of the bonding chamber. When a predetermined time elapses, the pressures on both sides become equal due to the microtubes 52 installed on the material 51. In other words, the pressure inside the PDP cell becomes equal to the original process pressure. When the pressure inside the PDP cell is equal to the process pressure, the micro tube 52 is removed outward as shown in FIG. 6D.

When the microtubes 52 are removed, the fluid material 51 is spread to the position where the microtubes 52 are placed by the surface tension to fill the microtube holes. At this time, it is obvious that the portion where the micro tube 52 was located also has the same width as the other portions. Here, the principle that the material 51 blocks the hole is due to the capillary phenomenon of the hole itself and the surface tension due to the fluidity of the material 51.

After the hole formed by the microtubes 52 is filled, the actual material 51 is cured to complete the exhaust, gas injection, and bonding processes of the panel, and the panel is unloaded from the plasma chamber to finish PDP manufacturing.

PDP manufacturing method according to the present invention configured as described above can prevent the increase in the discharge voltage generated in the actual process by using a plurality of micro tubes to match the pressure in the PDP cell to the process pressure durability and reliability of the product There is an advantage to improve.

Claims (5)

The first step of loading and cleaning the panel into the plasma chamber, and in order to make the discharge gas pressure in the PDP cell equal to the process pressure in the chamber, a plurality of microtubes penetrate the actual substrate on the lower substrate of the loaded panel A second step of mounting and coating the material, a third step of evacuating the inside of the plasma chamber and injecting a discharge gas, and a fourth step of bringing the upper and lower substrates together by aligning the lower and upper substrates; And a fifth step of removing the microtubes when the pressure of the plasma chamber and the pressure inside the panel match, and a sixth step of unloading the panel from the plasma chamber after curing the substance. Display panel manufacturing method. The method of claim 1, Wherein the second step is a plasma display panel manufacturing method characterized in that the coating on the micro tube to the actual material to be applied to more than the height of the rib formed on the lower substrate through several iterations. The method according to claim 1 or 2, The micro tube is a plasma display panel manufacturing method characterized in that evenly installed in all directions. The method according to claim 1 or 2 or 3, And the microtube has a diameter so that its diameter does not exceed the height of the rib formed on the lower substrate. The method of claim 1, The fifth step is a plasma display panel manufacturing method characterized in that the microtubes are removed in a state where the internal and external pressures of the panel are matched, and the fluid substance is naturally filled in the position where the microtubes exit.