JP2000106084A - Manufacture of plasma display panel and management of firing plate for manufacturing plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacture of a plasma display panel, including a firing process, wherein the camber amount of a firing plate is set in a certain range and its management. SOLUTION: This manufacture is that of a plasma display panel, including at least one firing process. A firing plate 10 is used for firing, wherein the camber amount of the firing plate 10 used in the firing process is 0.5 mm or less in maximum when it is measured with the firing plate 10 placed on a plate. Similarly, in its management, the camber amount of the firing plate 10 used in the firing process is 0.5 mm or less in maximum when it is measured with the firing plate 10 placed on a plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a plasma display panel (PDP) and the like. More specifically, the present invention relates to a method of manufacturing a PDP in which the amount of warpage of a fired plate is set within a predetermined range in a firing process of a PDP substrate, and a method of managing a fired plate for manufacturing a PDP.

[0002]

2. Description of the Related Art In general, a PDP has a structure in which a pair of electrodes arranged regularly on two opposing glass substrates are provided, and a gas mainly composed of Ne, Xe or the like is sealed between the electrodes. Then, a voltage is applied between these electrodes,
By generating a discharge in a minute cell around the electrode, each cell emits light to perform display. In order to display information, regularly arranged cells are selectively caused to emit light. There are two types of PDPs, a direct current type (DC type) in which the electrodes are exposed to the discharge space, and an alternating current type (AC type) in which the electrodes are covered with an insulating layer. And a refresh driving method and a memory driving method.

FIG. 7 is an exploded perspective view showing an example of the configuration of an AC type PDP. In this figure, the front plate and the rear plate are shown separated from each other.
Numerals 12 are arranged in parallel and opposed to each other, and both are held at a fixed interval by a partition 8 provided in parallel with each other on a glass substrate 11 serving as a back plate. On the rear side of the glass substrate 12 serving as a front plate, composite electrodes X and Y each composed of a sustain electrode 14 which is a transparent electrode and a bus electrode 13 which is a metal electrode are formed in parallel with each other, and a dielectric A layer 16 is formed, and a protective film 17 (MgO layer) is further formed thereon. Also,
On the front side of the glass substrate 11 serving as a back plate, the address electrodes 1 are located between the partition walls 8 so as to be orthogonal to the composite electrodes.
5 are formed in parallel with each other, and a phosphor layer 18 is provided so as to cover the wall surface of the partition 8 and the cell bottom surface. The AC type PDP is of a surface discharge type, and has a structure in which an AC voltage is applied between the composite electrodes X and Y on the front panel to discharge by an electric field leaking into the space. In this case, since the alternating current is applied, the direction of the electric field changes according to the frequency. Then, the phosphor layer 18 emits light by the ultraviolet light generated by the discharge, and the light transmitted through the front plate is visually recognized by the observer.

In manufacturing the back plate of the PDP as described above, an address electrode 15 is formed on a glass substrate 11,
Prior to providing the address electrode 15, if necessary, a base layer of a thin film made of low-melting glass is provided to prevent the diffusion of alkali components from the glass substrate and to improve the adhesion between the electrode and the dielectric with the substrate. Will be Furthermore, after forming the dielectric layer 17 so as to cover the electrode 15, a partition wall forming material is applied and dried, and further, a dry film resist is coated to form a pattern, etched, sandblasted, and baked. The partition 8 is formed. It is based on a method of providing a phosphor layer 18 between the partition walls 8. The phosphor layer 18 is provided by a method of selectively filling phosphor pastes of three colors of red (R), green (G), and blue (B) between the partition walls 8 by a screen printing method or the like.

On the other hand, in the manufacture of the front plate, a transparent sustain electrode 14 and a bus electrode are formed on a glass substrate 12 and fired.
Further, a dielectric layer 16 is formed thereon and fired. Finally, a protective film 19 made of magnesium oxide is formed. In the step of forming the back plate 11, after forming the underlayer,
After the formation of the address electrode, the formation of the dielectric layer, the formation of the partition, and the application of the phosphor layer, firing is performed in each of the five steps and, if necessary, after the repair of the electrode disconnection and the repair of the partition wall defect. Will be Also, in the step of forming the front plate 12, firing is performed in two steps after the formation of the electrodes and after the formation of the dielectric layer. As described above, in the manufacture of the plasma display panel, the firing process is frequently performed, and the firing is performed by mounting the substrate on the firing plate which is a flat glass substrate. Therefore, appropriate management regarding the flatness of the firing plate is performed. Has a significant effect on PDP substrate quality.

FIG. 5 is a schematic view showing a cross section of a firing furnace for firing a PDP substrate. In the firing step, the PDP substrate 11 to be fired is placed on the firing plate 10 and placed on a belt conveyor 21 with rollers. As shown in FIG. 5, a heating element 23 that emits far-infrared rays is provided on the upper and lower surfaces of the furnace wall 24, and the conveyor is run at a slow speed in the firing furnace 20 controlled at a constant temperature. The cycle time from loading to unloading to the firing furnace is usually about 3 hours, but the temperature is gradually raised over about 1.5 hours, and the maximum temperature is maintained for about several minutes. belongs to. Then, similarly, 1.5
A step of gradually cooling over a period of time is performed. The actual firing furnace is a line divided into blocks such as a low-temperature section, a heating section, a high-temperature section, and a falling-temperature section.

Although the PDP substrate can be directly placed on the conveyor roller 22 and transported and fired, in order to prevent scratches on the contact surface with the roller, usually a flat glass substrate is used. Then, the substrate is placed on a firing plate having a softening point higher than that of the PDP substrate and firing is performed. The surface of the roller is coated with ceramic. The PDP substrate is heated to a maximum of about 600 ° C. in a baking furnace and softened, but it is considered that the PDP substrate maintains elasticity without flowing. P
The partition wall material of the DP substrate is 500 ° C. to 550 which is lower than the softening temperature of the front or rear glass substrate.
A glass frit made of a low-melting glass or the like that can be fired at a temperature of ° C is used as a binder. Preferably up to 570 ° C-6
This is performed by heating to about 00 ° C.

As the material of the PDP substrate, a glass substrate such as aluminosilicate glass or borosilicate glass, crystallized glass (trade name of Corning) such as pyroceram, or quartz is used. ° C or higher softening point,
A glass plate made of a material such as crystallized glass is used. Although the thickness of the PDP substrate varies depending on the size, it is usually 2.0 to 3.0 mm.
Those having a size of 3.0 to 7.0 mm are used. The firing plate is PD
A substrate larger in size than the P substrate is used.
If the long side of the DP substrate is 450 mm, a fired plate having a corresponding side length of 500 mm is used. Increasing the softening temperature of the fired plate requires that the PDP substrate be softened to some extent to increase the adhesion to the partition wall material, etc., but the flatness of the PDP substrate cannot be maintained if the fired plate itself is deformed. It is.

By the way, a new fired plate delivered from a manufacturer usually has a certain flatness, but sometimes includes a warped plate, so that acceptance management is required.
Further, since the fired plate has high heat resistance, it does not warp under ordinary firing conditions, but often inevitably generates a slight warp due to the heat history in the furnace in the process of repeatedly using the fired plate. It is considered that this is because the baking plate is conveyed on the conveyor with rollers in the furnace, and the front and rear ends separated from the rollers 22 are thermally softened and bent downward by their own weight. A PDP substrate fired by such a warped firing plate reproduces the shape of the fired plate and causes warping. In particular, if there is a warp in the fired plate in the last firing step, restoration is not performed by subsequent firing, so that the final product is warped and a fatal defect. Even if it is not the last baking, it is clear that the warping of the baking plate will repeatedly force unnecessary warping and warping processes on the substrate and will have a bad effect on the address electrodes and partition walls. is there. It is conceivable that if the fired plate is used upside down, it may return to the original state. However, such a method of use is not performed because the back surface is often damaged by contact with the roller 22 in many cases.

[0010]

FIG. 6 is a view showing a state in which a warped PDP substrate is sealed. As shown in FIG. 6, the front glass substrate 12 and the rear glass substrate 11 are combined, and the periphery thereof is sealed by heating and melting an inorganic sealing glass agent or the like. In this case, the PDP substrate fired by the firing plate whose front and rear ends are warped downward has a convex central portion of both the front plate and the rear plate. When sealing is performed, the central portion of the substrate receives a high pressure, and the sealing portion receives a peeling force. Therefore, if the warpage is large, a gap is formed between the front panel and the rear panel, and the gas sealed in the panel leaks and the discharge becomes unstable, resulting in defective products. Generally, as a quality standard of such a PDP substrate, a 21-inch size (350 mm × 450 mm) and a warpage amount of 0.35 mm
Degree. Therefore, in the present invention, in order to obtain a PDP substrate that does not exceed such a criterion, the present inventors have studied how much the fired plate should be warped and completed the present invention.

[0011]

The first aspect of the present invention for solving the above-mentioned problems is a method for manufacturing a plasma display panel including at least one firing step, which is used in the firing step. The amount of warpage of the fired plate is represented by a maximum value when the fired plate is placed on a surface plate and measured, and the plasma is fired using a fired plate having a thickness of 0.5 mm or less. Display panel manufacturing method. Because of this manufacturing method, the flatness of the plasma display panel is high and defective products are rarely generated.

A second aspect of the present invention for solving the above-mentioned problems is a method for managing a fired plate used for manufacturing a plasma display panel, wherein the amount of warpage of the fired plate is determined. A method for managing a fired plate for manufacturing a plasma display panel, characterized in that it is controlled so as to be 0.5 mm or less, expressed as a maximum value when measured on a panel. With such a management method, the flatness of the plasma display panel is high and the occurrence of defective products can be reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The manufacturing process of a PDP according to the present invention is not different from the manufacturing of a normal PDP substrate except for a fired plate used in the firing process, but will be outlined below with reference to FIG. First, to manufacture the back plate, an electrode paste in which metals such as Ag, Ni, and Cu and their alloys are dispersed in a low-melting glass frit and a binder resin that can be fired at a low temperature on a cleaned glass substrate 11 for PDP. The address electrode 15 is formed using a material and is baked. Note that no base layer is provided. Next, a dielectric layer 17 made of low-melting glass is formed on the address electrode and fired. The dielectric layer is formed mainly for stability during driving, but also has an effect of protecting the partition from sandblasting by preventing the electrodes from being exposed.

Next, a material for forming a partition is applied and dried. A dry film resist is laminated thereon, and is exposed by an ultraviolet light source through a predetermined photomask to cure a portion where a partition is to be formed. Further development is performed to form a sandblast resist film. Using the resist film thus formed as a cutting mask, the partition wall forming material layer is cut by a sand blast method and baked to form the partition walls 8. Thereafter, the phosphor forming material is filled in the partition walls, the phosphor layer 18 is provided, and dried and fired to complete the back plate of the PDP. The front plate is manufactured in the same manner. First, the sustain electrode 14 and the bus electrode 13 are formed on the glass substrate 12 and fired. Next, a dielectric layer 16 is formed and fired, and a protective layer 19 is further formed to complete the process.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a PDP substrate is placed on a fired plate. FIG. 1A is a plan view thereof, and FIG.
FIG. 1B shows a cross section taken along line AA in FIG. The PDP substrate 11 is placed on a fired plate with the partition wall 8 formed within the dotted line facing upward. As a preferred embodiment of the fired plate, a state in which the fired plate is not warped and a PDP substrate is closely mounted as shown in FIG. 1 is preferable. As the baking plate 10, a baking plate having a size larger than that of the PDP substrate having the maximum size is usually used so as to be compatible with PDP substrates 11 of various sizes.

FIG. 2 shows a cross section when the fired plate is warped. FIG. 2A shows a state before firing, and PDP
The substrate 11 is flat but not in close contact with the warped firing plate 10. FIG. 2 (B) shows the state after firing, PD
The P substrate 11 is softened by heat and is warped along the shape of the fired plate 10. If the state shown in FIG. 2B is not the final firing, the original flat shape may be restored by the subsequent firing. However, if the final firing step is performed, the shape of the final product is not preferable. . If the amount of warpage of the last fired plate exceeds a certain amount, the warp exceeding the use limit value is left on the substrate, resulting in a defective product.

The amount of warpage of the fired plate can be measured as follows. As shown in FIG. 3, the fired plate 10 is placed on the surface plate 30 such that the convex portion is located at the center. The height of each part of the fired plate is measured by the dial gauge 31 using the upper surface of the surface plate as a reference surface. The difference between the maximum value (Dmax) and the minimum value (Dmin) of the measured values is defined as the amount of warpage (unit: mm) of the fired plate. In this case, it is assumed that the thickness of the fired plate is uniform. As shown in FIG. 4, the fired plate 10 is placed on the surface plate 30 such that the convex portion is located at the center. A gap gauge 32 is inserted between the upper surface of the surface plate and the side of the fired plate, and the maximum gap amount is defined as the warped amount (mm) of the fired plate. In the case of the gap gauge, the warp amount is on the side of the fired plate, and is a value approximating the maximum warpage amount of the fired plate.

[0018]

(Example 1) As a firing plate (1) in a final firing step, that is, a firing step after forming a phosphor layer, a 5.0 mm thick, size 5 made of zero-expansion crystallized glass was used.
One having a size of 00 mm x 400 mm was used ("Neoceram N-0" manufactured by NEC Corporation). The fired plate was used by heating an unused plate on a conveyor with rollers in a firing furnace to be warped, and having a warpage of 0.20 mm as measured by a dial gauge in FIG. On the other hand, a PDP substrate of soda glass having a thickness of 2.1 mm and a size of 350 mm × 450 mm was used (manufactured by Central Glass Co., Ltd.). Note that the PDP
The substrate was after the phosphor layer was applied and dried, and the amount of warpage of the PDP substrate was not recognized immediately before firing.
As shown in FIG. 1, this PDP substrate is
The DP substrate 11 was placed at the center of the baking plate so that the long sides became parallel, and baking was performed.

The processing process of the substrate before the final baking is as follows. <Electrode formation> After forming an address electrode using an electrode paste material composed of silver and a low melting point glass frit,
It was dried and fired. The firing conditions are as follows. -Furnace temperature 450 to 600 ° C-Firing time 2.5 to 3.0 hours The firing was performed every time the dielectric layer formation, partition wall formation, and phosphor layer formation were performed. Same as above.

<Formation of Dielectric Layer> A dielectric layer 1 having a thickness of 20 ± 2 μm was formed on the address electrode 15 of the glass substrate 11 using the dielectric layer forming material of the following [composition].
7 was formed by a screen printing method, dried at 170 ° C. and fired. [Composition] Glass frit [Main component: Bi ₂ O ₃ , ZnO ₂ , B ₂ O ₃ (alkali-free) Average particle size 3 μm] 70 parts by weight ・ TiO ₂ 3 parts by weight ・ Al ₂ O ₃ 7 parts by weight (above Softening point 570 ° C, Tg 485 ° C, coefficient of thermal expansion α ₃₀₀ = 80 × 10 ^-7 / ° C) of ethyl cellulose 7 parts by weight terpineol 15 parts by weight butyl cellosolve acetate 15 parts by weight

<Formation of Partition> The material for forming a partition having the following [composition] was applied on a substrate on which the electrode 15 and the dielectric layer 17 were formed by die coating, and dried at 170 ° C. [Composition]-Glass frit [MB-008, manufactured by Matsunami Glass Industry Co., Ltd.] 65 parts by weight-α-alumina RA-40 (Iwatani Chemical Industry) 10 parts by weight-Dipiroxide Side Black # 9510 (Dainichi Seika Kogyo Co., Ltd.) 10 parts by weight ・ Ethyl cellulose 2 parts by weight ・ Terpionaire 15 parts by weight ・ Butyl cellosolve acetate 15 parts by weight

On the PDP panel member thus obtained, a negative dry film resist having a protective film was laminated with a hot roll. Next, a line pattern mask was positioned and arranged on the dry film resist having the protective film, irradiated with ultraviolet rays, and developed to obtain a resist pattern corresponding to the line pattern mask.

Next, using the resist pattern as a mask, sandblasting was performed using a sandblasting apparatus. Thereafter, the resist pattern was peeled off, washed with water, dried in an oven at 80 ° C. for 15 minutes, and then baked.

<Formation of Phosphor Layer> After the partition of the back plate is completed, phosphor pastes of three colors of red (R), green (G) and blue (B) are selectively filled between the partitions 8 by a screen printing method. The method was performed in the following manner. The amount of warpage of the PDP substrate obtained by using the fired plate (1) after firing was 0.15 mm, which satisfied the acceptance reference value.

(Example 2) As the firing plate (2) in the last firing step, that is, the firing step after the phosphor layer is formed,
Using the same material and the same size fired plate as in Example 1,
A piece processed under the same conditions so as to have a warpage of 0.40 mm was prepared and used. Also, the same material and the same size were used as the PDP substrates. As in Example 1, the amount of warpage of the PDP substrate was not recognized immediately after the phosphor layer was applied and dried on the PDP substrate and immediately before firing. The amount of warpage of the PDP substrate obtained by using the fired plate (2) after firing was 0.30 mm, which satisfied the acceptance reference value.

(Example 3) As a firing plate (3) in the last firing step, that is, the firing step after forming the phosphor layer,
Using the same material and the same size fired plate as in Example 1,
A substrate processed under the same conditions so that the warpage amount was 0.50 mm was prepared and used. Also, the same material and the same size were used as the PDP substrates. As in Example 1, the amount of warpage of the PDP substrate was not recognized immediately after the phosphor layer was applied and dried on the PDP substrate and immediately before firing. The warpage after firing of the PDP substrate obtained using the firing plate (3) was 0.34 mm, which satisfied the acceptance reference value.

(Comparative Example 1) As the firing plate (4) in the last firing step, that is, the firing step after the phosphor layer was formed,
Using the same material and the same size fired plate as in Example 1,
A substrate processed under the same conditions so that the amount of warpage was 0.56 mm was prepared and used. Also, the same material and the same size were used as the PDP substrates. As in Example 1, the amount of warpage of the PDP substrate was not recognized immediately after the phosphor layer was applied and dried on the PDP substrate and immediately before firing. The amount of warpage of the PDP substrate obtained by using the fired plate (4) after firing was 0.40 mm, which did not satisfy the acceptance reference value.

(Comparative Example 2) As the firing plate (5) in the last firing step, ie, the firing step after the phosphor layer was formed,
Using the same material and the same size fired plate as in Example 1,
An article processed under the same conditions so that the amount of warpage was 0.66 mm was produced and used. Also, the same material and the same size were used as the PDP substrates. As in Example 1, the amount of warpage of the PDP substrate was not recognized immediately after the phosphor layer was applied and dried on the PDP substrate and immediately before firing. The amount of warpage of the PDP substrate obtained by using the fired plate (5) after firing was 0.50 mm, which did not satisfy the acceptance reference value.

Table 1 summarizes the results of the above embodiment and comparative example.

[Table 1]

From the above results, it can be seen that the amount of warpage of the fired plate is 0.5
In the case of 0 mm, the acceptance standard value is satisfied and 0.50 mm
If it exceeds, it becomes clear that the acceptance criteria are not met. This means that the length of the long side of the fired plate is 500 mm
Is about 0.50 mm or less, it can be said that the reference value roughly satisfies the reference value (0.35 mm for a 21-inch size). When this value is represented by (warpage amount / length of the long side of the fired plate), the value is from 0.50 / 500 mm to 0.001. In addition, if such a numerical value is used as the standard for the management of the fired plate, it can be used for accepting the fired plate and managing the process.

[0031]

According to the method of manufacturing a plasma display panel according to the present invention, since the amount of warpage of the fired plate falls within a predetermined range, a PDP substrate of a constant quality can be manufactured. A gap is created between the face plate and the back plate, and problems such as leakage of gas sealed in the panel and unstable discharge do not occur. Therefore, the PDP yield can be improved. Also, according to the present invention, P
According to the method for managing the fired plate for DP, the fired plate is controlled to have a constant warpage amount, so that the same effect can be obtained.

[Brief description of the drawings]

FIG. 1 shows a state in which a PDP substrate is mounted on a fired plate.

FIG. 2 shows a cross section when a fired plate is warped.

FIG. 3 shows a method for measuring the amount of warpage of a fired plate using a dial gauge.

FIG. 4 shows a method of measuring the amount of warpage of a fired plate using a gap gauge.

FIG. 5 is a schematic view showing a cross section of a firing furnace for firing a PDP substrate.

FIG. 6 is a view showing a state in which a warped PDP substrate is sealed.

FIG. 7 is an exploded perspective view showing a configuration example of an AC type PDP.

[Explanation of symbols]

 Reference Signs List 8 partition wall 9 sealant 10 firing plate 11, 12 glass substrate (PDP substrate) 13 bus electrode 14 sustain electrode 15 address electrode 15e terminal electrode 16, 17 dielectric layer 18 phosphor layer 19 protective film (MgO layer) 20 firing furnace 21 Belt Conveyor 22 Roller 23 Heating Element 24 Furnace Wall 30 Surface Plate 31 Dial Gauge 32 Gauge

Claims (5)

[Claims] 1. A method for manufacturing a plasma display panel including at least one firing step, wherein a maximum amount of warpage of a fired plate used in the firing step is measured when the fired plate is placed on a surface plate. A method for manufacturing a plasma display panel, comprising firing using a firing plate having a value of 0.5 mm or less. 2. The method according to claim 1, wherein the firing step is the last firing step. 3. A value represented by (amount of warpage / long side length of fired plate) is 0.001 or less.
A method for manufacturing a plasma display panel according to claim 2. 4. A method for managing a fired plate used for manufacturing a plasma display panel, comprising:
A method for managing a fired plate for manufacturing a plasma display panel, characterized in that the fired plate is controlled to be 0.5 mm or less, expressed as a maximum value when the fired plate is mounted on a surface plate and measured. 5. A numerical value represented by (amount of warpage / length of long side of fired plate) is 0.001 or less.
The method for managing a fired plate for manufacturing a plasma display panel according to the above.