KR19990043617A - Manufacturing Method of Plasma Display Device - Google Patents

Abstract

The present invention discloses an improved method of making PDPs.

Conventionally, sealing and exhausting and charging of the PDP panel are performed in separate processes, and thus, manufacturing facilities are separate, manufacturing cost and power consumption are large, and manufacturing time is large.

The present invention solves the conventional problem by heating the panel to a firing temperature on the exhaust and filling device to seal the firing and then cooling it to the exhaust temperature to perform high temperature exhaust.

Description

Manufacturing Method of Plasma Display Device

The present invention relates to a method of manufacturing a plasma display panel (PDP).

In Fig. 1, the basic configuration of the PDP using the gas discharge phenomenon for image display is to charge the discharge gas between the two substrates P1 and P2 on which the opposite electrodes E1 and E2 are arranged, and to prevent the interference between the selected pixels. It is a direct current (DC) type PDP partitioned by barrier ribs (B).

However, since the DC type PDP has a limited duty cycle, display of a high resolution moving image is impossible, so that a dielectric layer D is formed on one of the electrodes E1 and E2 to form wall charge. AC (P) type PDPs are mainly used to improve the performance.

Here, the dielectric layer D is formed on the opposite side of the fluorescent layer F. When the fluorescent layer F is to be formed on the front substrate P1, a thin and uniform fluorescent layer F is difficult to form. (F) is generally formed to have a substantially U-shaped cross section girth on the back substrate P2 side, whereby the dielectric layer D is formed on the front substrate P1 side.

In particular, the configuration shown is a surface discharge type PDP, and the front electrode E1 under the dielectric layer D is composed of a plurality of parallel electrodes E1a and E1b, so that the back electrode E2 on the opposite side and the start discharge are formed. After the above, the sustain discharge is caused between the parallel electrodes E1a and E1b to further increase the luminance of light emitted.

On the other hand, the dielectric layer (D) or the like is generally formed by a thick film method such as printing, in which case a so-called ion bombard in which plasma penetrates into the gap between the dense dielectric layer (D) and damages the electrode (E1). Since an ion bombardment phenomenon occurs, the protective layer T is formed on the dielectric layer D by a thin film to prevent the ion bombardment.

In the manufacturing process of the PDP, the required functional layers such as the electrodes E1 and E2 and the partition walls B are formed on each of the substrates P1 and P2, and then the both substrates P1 and P2 are sealed to seal the panel ( After the panel is formed, the cavity of the panel is exhausted, and the required discharge gas is injected and sealed.

Figure 2 shows the sealing process of the PDP first, as shown in (A) is coated with the sealing material (S) on the outer periphery of one of the substrates (P2) and then placed on the other substrate (P1), such as (B) It is achieved by firing the encapsulant S on a heating schedule.

Here, the firing of the panel is mainly carried out through a tunnel-type firing furnace, and thus, sequence and slow cooling are required to prevent thermal shock damage of the glass panel. As shown, a heating zone (0 to t1 ') to the firing temperature (T1), a holding zone (t1' to t2 ') at the firing temperature (T1), and cooling back to room temperature It has a cooling zone (t2 'to t3') to have a roughly trapezoidal shape.

Meanwhile, the enclosed panel is exhausted and filled as shown in FIG. 3, and a vacuum pump 20 and a cleaning gas are provided on the exhaust head 10 connected to the cavity of the panel P of one or more (dotted lines). The supply source 40 and the filling gas supply source 30 are respectively connected.

The charging process of the discharge gas is a process of injecting and filling the discharge gas after cleaning the cavity of the panel P by repeatedly injecting and evacuating the cleaning gas.

However, as described above, the functional layers E1, E2, and B on the substrates P1 and P2 are mainly made of a printing method, and most of the organic solvents used for the composition of the paste for printing are discharged during the firing process. In order to facilitate its removal, so-called out-gassing, a high temperature exhaust process in which the panel P is heated while heated to a high temperature state is mainly adopted.

The high temperature exhaust also serves to promote the exhaust by expanding the volume of residual gas in the cavity, and the heating process includes a temperature range (0 to t1 ") up to the exhaust temperature T2 as shown in FIG. It consists of a holding table (t1 "to t2") and a cooling table (t2 "to t3"), the temperature and time difference, but has a heating schedule similar to the sealing process.

The process of the high temperature exhaust is mainly composed of a batch processing device in the configuration of the exhaust and filling device is processed.

As described above, in the conventional PDP manufacturing process, a sealing process and a high temperature exhaust process are performed separately. As described above, in order to prevent breakage due to thermal shock of the glass panel P, each process requires sequence and slow cooling, and thus takes several tens of minutes. This significantly consumes the overall heating power and manufacturing time.

In addition, the fluorescent layer F, which is susceptible to heat, undergoes repeated heating cycles and is easily deteriorated. Furthermore, the panel P itself is made of glass, which is a solid solution having a large deformation such as creep. There is considerable deformation by heating.

Particularly, in the case of AC type PDP, the protective layer T stacked on the dielectric layer D has a large difference in coefficient of thermal expansion, so that cracks are generated and whitened due to such repeated heating. It will also lead to a failure.

SUMMARY OF THE INVENTION In view of the various problems of the related art, an object of the present invention is to provide a PDP manufacturing method which can prevent degradation of panels and functional layers and greatly reduce PDP manufacturing time and power consumption.

1 is a cross-sectional view of an AC type PDP as an example of the PDP;

The second (A) and (B) is a schematic cross-sectional view and a heating schedule for explaining the sealing process of the PDP,

3 (A) and (B) is a system diagram and a heating schedule for explaining the exhaust process of the PDP,

4 is a system diagram illustrating the method of the present invention;

5 is the heating schedule.

* Explanation of symbols for main parts of the drawings

P: (PDP) panel P1, P2: substrate

S: sealant T1: firing temperature (of the sealant)

T2: Exhaust temperature (of panel)

In order to achieve the above object, the PDP manufacturing method according to the present invention installs a panel of a pre-assembled state in which an encapsulant is applied on an exhaust and filling device, and raises and maintains the encapsulant by raising and maintaining it to the firing temperature of the panel. Thus, the panel is sealed, the panel is cooled and maintained at an exhaust temperature, the cavity is evacuated, and the discharge gas is charged.

According to this configuration, the sealing, evacuation, and filling of the PDP panel is completed in only one heating cycle, which significantly shortens the time, reduces the heating power, and reduces the cost of equipment by unifying the firing apparatus and the exhaust apparatus into one.

In addition, since the substrate and functional layers of the panel undergo only one heating cycle, the deformation and deterioration can be reduced and prevented.

Accordingly, the present invention has a big advantage that can quickly implement high quality PDP at low manufacturing cost.

(Example)

Such specific features and advantages of the present invention will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

In FIG. 4, the exhaust and filling device is constructed by connecting a vacuum pump 20 and a cleaning and filling gas supply source 40, 30 to the exhaust head 10 as in the related art.

Thus, the exhaust and charging device itself is similar to the conventional configuration, but according to the characteristics of the present invention, in the exhaust and charging device, the encapsulant (S) is applied between the two substrates (P1, P2) and the panel (P) of the preassembled state which has not yet been fired. ), For example, a panel (P) holding the two substrates (P1, P2) only by drying the suture (S) will be installed, so a suitable jig for preventing the flow of the panel (P), etc. Will be needed.

Alternatively, a method of constructing the panel P by installing the back substrate P2 on the exhaust and filling device first, applying the encapsulant S thereto, and then placing the front substrate P1 thereon may be considered. In view of the difficulty of the process, it is more preferable to install the panel P in the preassembled state as described above.

When the panel P in the temporarily assembled state is installed, the panel P is first sealed. To this end, as shown in FIG. 5, the temperature of the panel P is raised to a firing temperature T1 (temperature rising zone; 0 to t1). The first holding zone (t1 to t2). Then, the encapsulant S is fired to tightly seal the two substrates P1 and P2. In this process, impurities such as residual organic materials remaining in the functional layers are discharged together, that is, outgassed.

Preferably, the temperature increase rate of the temperature rising zone (0 to t1) is 0.7 ° to 2.0 ° C / min, and the firing temperature (T1) maintained at the first holding zone (t1 to t2) is about 20 to about 410 to 450 ° C. It lasts 40 minutes. Here, 0 means room temperature (generally 20 ° C.), not 0 ° C., therefore, the time required for the temperature rise is about 3 hours to 10 hours.

When the sealing is completed in the first holding zone (t1 to t2), the temperature of the panel P is lowered to the exhaust temperature T2, and the cooling rate of the first cooling zones t2 to t3 is preferably It becomes about 0.5-1 degree-C / min.

The exhaust temperature T2 in the second holding zones t3 to t4 is preferably 340 to 370 ° C, and the holding time is about 3 to 4 hours. Accordingly, the cooling time of the first cooling zone (t2 to t3) takes about 20 to 140 minutes.

In the exhaust process, first, the vacuum pump 20 is operated to remove air in the cavity of the panel P together with residual impurities, and then maintain the vacuum state. The panel P is cleanly exhausted by repeating the process of injecting a cleaning gas such as N ₂ from the gas 40 and evacuating the same.

Since the charging and discharging of the discharge gas should be performed at a temperature close to the room temperature of the panel P, when the exhaust is finished, the second cooling zone t4 to cool the panel P to room temperature from the end point of the second holding zone t3 to t4. t5) is disclosed. At this time, the end point of the second cooling zone (t4 ~ t5) is the injection point of the discharge gas, the temperature at this time may be room temperature, but since the charging pressure of the discharge gas is lower than the atmospheric pressure at a temperature higher than the room temperature for convenience of injection Can be done.

At this time, the cooling rate of the second cooling zone (t4 ~ t5) is preferably 1.0 to 2.0 ℃ / min takes about 3 to 7 hours.

Accordingly, the total time required for injection charging of the discharge gas is about 12 hours 40 minutes to 25 hours 40 minutes.

Compared with the method of the present invention as compared with the conventional method of Figs. 2 and 3, the time saved in the manufacturing process is increased from the room temperature to the exhaust temperature (T2; 340 ℃ ~ 370 ℃) and the firing temperature (T1; 390 ~ 430 ℃) ) Is a time required for cooling from room temperature to a bar. For convenience of comparison, assuming that the temperature and cooling rate are 1 ° C./min, the process time reduction according to the present invention is about 13 hours 10 minutes to 16 hours 20 minutes. It is possible to reduce the process time by at least about 40%.

In addition, since the panel P is subjected to a single heating cycle as a whole, deterioration or damage of the fluorescent layer Y or the protective layer T, which is particularly susceptible to heat, is prevented and the deformation of the glass substrates P1 and P2 is reduced. Can be.

The present invention is also unified with the firing furnace for sealing and the heating furnace for exhaust, the installation cost and space occupied, process moving equipment and man-hours, etc. can be reduced, power consumption can be greatly reduced.

Accordingly, the present invention has a great effect of quickly manufacturing high quality PDP with low production cost and high productivity.

Claims (6)

In a method of manufacturing a plasma display device in which a panel is formed by applying and baking a sealing material between two substrates, and the cavity of the panel is evacuated to inject and charge a discharge gas. By installing the panel of the prefabricated state coated with the sealing material on the exhaust and filling device, After the panel is heated and maintained to a firing temperature, the panel is sealed by firing the encapsulant. And discharging the cavity of the panel to charge and discharge the panel by cooling and maintaining the panel at an exhaust temperature. The method of claim 1, The firing temperature of the encapsulant is maintained at 410 to 450 ℃ 20 to 40 minutes characterized in that the manufacturing method of the plasma display device. The method according to claim 1 or 2, Method for manufacturing a plasma display device, characterized in that the temperature increase rate from room temperature to the firing temperature is 0.7 to 2.0 ℃ / min. The method of claim 1, Method for manufacturing a plasma display device, characterized in that the exhaust temperature of the panel is maintained for 3 to 4 hours at 340 to 370 ℃. The method according to any one of claims 1, 2 or 4, And a cooling rate from the firing temperature to the exhaust temperature is 0.5 to 1 deg. C / min. The method according to any one of claims 1 to 4, And a cooling rate from said exhaust temperature to room temperature is 1.0 to 2.0 deg. C / min.