JP3372028B2 - Plasma display panel, manufacturing method and manufacturing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel used for a display of a color television receiver and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a plasma display panel (hereinafter referred to as PDP) in a display device used in a computer, a television, etc. has been noted as a device that can realize a large size, a thin shape and a light weight. Therefore, the demand for high-definition PDP is increasing.

FIG. 29 shows a general AC (AC) type PD.
It is a schematic sectional drawing which shows an example of P. In this figure, a display electrode 102 is formed on a front glass substrate 101, and the display electrode 102 is covered with a dielectric glass layer 103 and a dielectric protective layer 104 made of magnesium oxide (MgO) (for example, Japanese Patent Laid-Open No. HEI 5). -342991 publication).

Address electrodes 106 and partition walls 107 are provided on the rear glass substrate 105.
A phosphor layer 110 of each color (red, green, blue) in the gap between the seven
~ 112 are provided. The front glass substrate 101 is disposed on the partition wall 107 of the rear glass substrate 105, and the discharge gas is sealed between the both substrates 101 and 105 so that the discharge space 10 is formed.
9 is formed.

In this PDP, vacuum ultraviolet rays (mainly having a wavelength of 147 nm) are generated in the discharge space 109 due to the discharge, and the phosphor layers 110 to 112 of the respective colors are excited and emitted to perform color display. The PDP can be manufactured as follows. Front glass substrate 101
Then, a silver paste is applied and baked to form a display electrode 102, a dielectric glass paste is applied and baked to form a dielectric glass layer 103, and a protective layer 104 is formed thereon.

On the rear glass substrate 105, silver paste is applied and baked to form address electrodes 106, and glass paste is applied and baked at a predetermined pitch to form partition walls 107. Then, phosphor paste of each color is applied between the partition walls 107, and the phosphor layers 110 to 112 are formed by removing the resin component and the like in the paste by baking at about 500 ° C.

After the phosphor is fired, a glass frit for sealing is applied around the rear glass substrate 105 and calcined at about 350 ° C. to remove the resin component and the like in the formed sealing glass layer (temporary frit). Baking process). Then, the front glass substrate 101 and the rear glass substrate 105 are stacked so that the display electrodes 102 and the address electrodes 106 are orthogonal to each other and face each other. Then, this is heated to a temperature higher than the softening temperature of the glass for sealing (about 450 ° C.) to perform sealing (sealing step).

Thereafter, while heating the sealed panel up to about 350 ° C., an internal space formed between both substrates (a space formed between the front plate and the back plate and facing the phosphor).
After that, the discharge gas is introduced so as to have a predetermined pressure (usually 300 to 500 Torr).

[0009]

In the PDP manufactured as described above, there is a problem of how to improve the light emission characteristics including improving the brightness. Therefore, for example, the emission characteristics of the phosphor itself have been improved, and further, it is desired to make a PDP having excellent emission characteristics.

Further, using the manufacturing method as described above, P
Although DP is being mass-produced, the production cost of PDP is considerably higher than that of CRT at present, and it is desired to lower the cost. There are various possibilities to reduce the cost in manufacturing a PDP, but for example, the energy consumption and labor (working time) required in some processes that require heating as described above.
Considering that the value is large, it is desirable to reduce these as one solution.

A first object of the present invention is to provide a PDP which operates with high luminous efficiency and has good color reproducibility.
In manufacturing P, calcination process, sealing process, exhaust process,
A second object is to reduce the manufacturing cost by providing a method that can be performed with short working time and low energy consumption.

[0012]

Means for Solving the Problems The first purpose is to provide PD
In P, the color temperature of the emission color when all the cells are turned on under the same power condition is 7,000 K or more, preferably,
This can be achieved by setting the temperature to 8,000K or higher, 9000K or higher, and 10,000K or higher. As described above, in order to increase the color temperature in the white balance, it is important to improve the emission chromaticity of the blue phosphor layer, and the chromaticity coordinate y (of the emission color when only the blue cell is turned on) CI
E color system) or the blue phosphor layer should be such that the chromaticity coordinate y of the light emitted when excited by vacuum ultraviolet rays is 0.08 or less, preferably 0.07 or less, 0.06 or less. Good. Alternatively, the peak wavelength in the emission spectrum when only the blue cell is turned on may be 455 nm or less, preferably 453 nm or less and 451 nm or less.

If the emission chromaticity of the blue phosphor layer is improved as described above, the color reproducibility is also improved. As described above, the PDP having excellent emission chromaticity of the blue phosphor layer has a step of heating the disposed phosphor in the step of manufacturing the PDP (phosphor firing step, sealing material calcination step , Sealing step, evacuation step, etc.) in a dry gas atmosphere or an atmosphere in which the dry gas flows under reduced pressure.

That is, the present inventors have found that in the conventional PDP manufacturing method, the blue phosphor is thermally deteriorated in the step of heating the phosphor layer, and the emission intensity and emission chromaticity of the blue phosphor are reduced. By using the above manufacturing method,
It is possible to prevent this thermal deterioration. Here, the "dry gas" is a gas having a steam partial pressure smaller than usual, and it is preferable to use dried air (dry air).

The partial pressure of water vapor in the atmosphere of dry gas is 1
It is preferably 5 Torr or less, and further 10 To
rr or less, 5 Torr or less, 1 Torr or less, 0.5T
It is preferable to set it to or or less. It can be said that the dew point temperature of the dry gas is preferably 20 ° C. or lower, more preferably 10 ° C. or lower, 0 ° C. or lower, −20 ° C. or lower, −40 ° C. or lower.

As described above, in the PDP having the blue phosphor layer with excellent emission chromaticity, the front substrate and the rear substrate are calcined in a state where the facing surfaces are open, and the front substrate and the rear substrate are inside space. It is also manufactured by using a method of sealing while flowing a dry gas to the substrate, or a method of preheating the front substrate and the rear substrate in a state where the facing surfaces are opened and then sealing the both substrates by stacking them. be able to.

Further, after performing a sealing step of sealing the sealing material at the sealing temperature in a state where the front panel substrate and the rear panel substrate are superposed on each other, they are sealed without lowering to room temperature. After starting the exhausting step of exhausting the gas in the internal space between the two substrates, or after the sealing material calcination step of calcining the substrate provided with the sealing material at the calcination temperature, By starting the sealing process without lowering the temperature of the substrate to room temperature, the first and second objects can be achieved.

That is, in the actual manufacturing process, each of these processes is performed using a heating furnace, but conventionally, the sealing material calcination process, the sealing process, and the exhaust process are generally performed separately. Since the substrate was cooled to room temperature between the steps, it takes a long time and a lot of energy to reheat and raise the temperature in the later step.
As described above, if the process is performed between the processes without lowering the temperature of the substrate to room temperature, the time required for heating and the energy consumption can be reduced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a perspective view showing a main part of an AC surface discharge type PDP according to an embodiment, in which a display region in a central portion of the PDP is partially shown. It is shown in the figure. This PDP has a front panel substrate 1 in which display electrodes 12 (scan electrodes 12a, sustain electrodes 12b), a dielectric layer 13, and a protective layer 14 are arranged on a front glass substrate 11.
0 and the rear panel substrate 20 having the address electrodes 22 and the dielectric layer 23 on the rear glass substrate 21 are parallel to each other with the display electrodes 12a, 12b and the address electrodes 22 facing each other. It is arranged and configured.
The gap between the front panel substrate 10 and the rear panel substrate 20 is partitioned by the partition wall 24 in a stripe shape to form a discharge space 30, and the discharge space 30 is filled with a discharge gas.

In the discharge space 30, a phosphor layer 25 is arranged on the rear panel substrate 20 side. The phosphor layers 25 are repeatedly arranged in the order of red, green and blue. The display electrode 12 and the address electrode 22 are
Both are stripe-shaped, the display electrodes 12 are arranged in a direction orthogonal to the partition walls 24, and the address electrodes 22 are arranged in parallel with the partition walls 24. Then, the display electrode 12 and the address electrode 2
A panel structure is formed in which cells that emit red, green, and blue colors are formed where the two intersect.

When driving the PDP, a drive circuit (not shown) applies an address discharge pulse to the scan electrode 12a and the address electrode 22 to accumulate wall charges in the cell to be made to emit light. After that, the operation of performing sustain discharge in the cells in which the wall charges are accumulated by applying the sustain discharge pulse to the display electrode pair 12a and 12b is repeated to perform the light emission display.

The address electrode 22 is a metal electrode (for example,
A silver electrode or a Cr-Cu-Cr electrode). The display electrode 12 has an electrode configuration in which a bus electrode (silver electrode, Cr—Cu—Cr electrode) having a narrow width is laminated on a wide transparent electrode made of a conductive metal oxide such as ITO, SnO ₂ or ZnO. It is preferable to set the resistance of the display electrode to be low and to secure a large discharge area in the cell.
Similarly to the above, a silver electrode can be used.

The dielectric layer 13 is a layer made of a dielectric material, which is arranged so as to cover the entire surface of the front glass substrate 11 on which the display electrodes 12 are arranged. Generally, a lead-based low melting point glass is used. However, it may be formed of a bismuth-based low melting point glass or a laminate of a lead-based low melting point glass and a bismuth-based low melting point glass. The protective layer 14 is made of magnesium oxide (Mg
It is a thin layer of O) and covers the entire surface of the dielectric layer 13.

The dielectric layer 23 is similar to the dielectric layer 13, but TiO ₂ particles are mixed so as to also function as a visible light reflecting layer. The partition wall 24 is made of a glass material and is provided so as to project on the surface of the dielectric layer 23 of the rear panel substrate 20. As the phosphor material forming the phosphor layer 25, here, a blue phosphor: BaMgAl ₁₀ O ₁₇ : Eu green phosphor: Zn ₂ SiO ₄ : Mn red phosphor: Y ₂ O ₃ : Eu is used. .

The composition of these phosphor materials has conventionally been P.
It is basically the same as that used for DP,
As compared with the phosphor layer in the conventional PDP, the degree of heat deterioration of the phosphor in the manufacturing process is small, and thus the emission color is better. Here, good emission color means
The chromaticity coordinate y value of the light emitted by the blue cell is small (the peak wavelength of blue light emission is short), and the color reproduction range near blue is wide.

In the conventional general PDP, the chromaticity coordinate y (CIE color system) of the emission color when only the blue cell is turned on is 0.085 or more (the peak wavelength of the emission spectrum is 456 nm or more). The color temperature is about 6000K with white balance without color correction. As a technique for improving the color temperature in this white balance, for example, a technique in which only the width of the blue cell (partition pitch) is set large and the area of the blue cell is made larger than the area of the green cell or the red cell is also known. However, in order to increase the color temperature to 7,000 K or higher by this method, the area of the blue cell must be set to about 1.3 times or more the area of the green cell or the red cell.

On the other hand, in the PDP of this embodiment,
The chromaticity coordinate y of the emission color when only the blue cell is turned on is 0.08 or less, and the peak wavelength of the emission spectrum is 455n.
m or less, which makes it possible to set the color temperature to 7,000 K or more in white balance without color correction without particularly setting the area of the blue cell large. Also, depending on the manufacturing conditions, the chromaticity coordinate y can be made lower, and the color temperature is 100 with white balance without color correction.
It is possible to set it to about 00K.

The fact that the value of the chromaticity coordinate y of the blue cell is small and the peak wavelength of blue light emission is short have the same meaning, which will be described in the third and fifth embodiments. Further, the smaller the value of the chromaticity coordinate y of the blue cell, the wider the color reproduction range, and the relationship between the chromaticity coordinate y value of the light emitted by the blue cell and the color temperature in white balance without color correction. This will be described in detail in a later example.

In the present embodiment, the film thickness of the dielectric layer 13 is about 20 μm and the film thickness of the protective layer 14 is about 0.5 μm according to the 40-inch class high-definition television. The height of the partition wall 24 is 0.1 to 0.15 m.
m, partition pitch 0.15 to 0.3 mm, phosphor layer 25
The film thickness is 5 to 50 μm. Further, the discharge gas to be sealed is Ne-Xe system, the content of Xe is 5% by volume, and the sealing pressure is set in the range of 500 to 800 Torr.

At the time of driving the PDP, as shown in FIG.
After each driver and panel drive circuit 100 is connected to the PDP, and a voltage is applied between the scan electrode 12a and the address electrode 22 of the cell to be lit to perform address discharge, a pulse voltage is applied between the display electrodes 12a and 12b. Apply and sustain discharge. Then, in the cell, ultraviolet rays are emitted with the discharge, and the phosphor layer 25 converts the light into visible light. An image is displayed by lighting the cell in this manner.
[Production Method of PDP] Hereinafter, the PDP having the above configuration
A method of manufacturing the will be described.

(Production of Front Panel Substrate) The front panel substrate 10 has a display electrode 12 formed by applying a silver electrode paste on the front glass substrate 11 by screen printing and then baking the paste to cover it. As described above, a lead-based glass material (the composition of which is, for example, lead oxide [PbO] 70% by weight, boron oxide [B ₂ O ₃ ] 15% by weight, silicon oxide [Si 2
O ₂ ] 15% by weight. Is applied by a screen printing method and baked to form a dielectric layer 13, and a protective layer 14 made of magnesium oxide (MgO) is further formed on the surface of the dielectric layer 13 by a vacuum deposition method or the like. It is made by

(Preparation of Back Panel Substrate) The back panel substrate has a rear glass substrate 21 on which an address electrode 22 is formed by screen-printing a paste for a silver electrode and then firing the paste, and TiO ₂ particles are formed on the address electrode 22. And a dielectric glass particle are applied by a screen printing method and baked to form a dielectric layer 23, and the same glass particle containing paste is repeatedly applied at a predetermined pitch using the screen printing method. The partition wall 24 is formed by firing.

Then, red, green, and blue phosphor pastes of respective colors are prepared, applied to the gaps between the partition walls 24 by a screen printing method, and fired in the air as described in detail later, whereby phosphors of respective colors are formed. The body layer 25 is formed. Each color phosphor paste used here can be manufactured as follows.

Blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu)
Is, as a raw material, barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ), aluminum oxide (α-A
1 ₂ O ₃ ) is blended so that the atomic ratio of Ba, Mg, and Al is 1: 1: 10. Next, a predetermined amount of europium oxide (Eu ₂ O ₃ ) is added to this mixture. And
Mix with an appropriate amount of flux (AlF ₂ , BaCl ₂ ) in a ball mill, and under a reducing atmosphere (in H ₂ , N ₂ ) for a predetermined time (for example, 0.5 hours), temperature 1400 ° C to 1650 ° C.
It is obtained by firing at.

For the red phosphor (Y ₂ O ₃ : Eu), a predetermined amount of europium oxide (Eu ₂ O ₃ ) is added to yttrium hydroxide Y ₂ (OH) ₃ as a raw material. Then, it is obtained by mixing with an appropriate amount of flux in a ball mill and firing in air at a temperature of 1200 ° C to 1450 ° C for a predetermined time (for example, 1 hour). Green phosphor (Zn ₂ Si
O ₄ : Mn) is mixed with zinc oxide (ZnO) and silicon oxide (SiO ₂ ) as raw materials so that the atomic ratio of Zn and Si is 2: 1. Next, a predetermined amount of manganese oxide (Mn ₂ O ₃ ) is added to this mixture. Then, after mixing with a ball mill, the temperature is set to 1
It is obtained by firing at 200 ° C to 1350 ° C.

By pulverizing and sieving each color phosphor thus produced, each color phosphor particle having a predetermined particle size distribution can be obtained. A phosphor paste of each color is obtained by mixing the phosphor particles of each color with a binder and a solvent. When forming the phosphor layer 25, in addition to the screen printing method described above, a method of scanning while ejecting phosphor ink from a nozzle, or a method of using a photosensitive resin containing phosphor materials of respective colors It can also be formed by a method of producing a sheet, adhering the sheet to the surface of the rear glass substrate 21 on which the partition wall 24 is arranged, patterning by photolithography, and developing to remove an unnecessary portion.

(Sealing of Front Panel Substrate and Back Panel Substrate, Vacuum Evacuation, Filling with Discharge Gas) Either one or both of the front panel substrate 10 and the rear panel substrate 20 thus prepared are coated with a glass frit for sealing. To form a sealing glass layer, which is calcined to remove resin components and the like in the glass frit, as will be described in detail later, and the display electrode 12 of the front panel substrate 10 and the address electrode 22 of the rear panel substrate 20 are formed. And are overlapped so as to be orthogonal to each other, and both of the overlapped substrates 10 and 20 are heated as described in detail later to soften the sealing glass layer to seal the substrates.

Then, the panel is fired while evacuating the inner space of the sealed panel substrate (at 350 ° C. for 3 hours). Then, a discharge gas having the above composition is sealed at a predetermined pressure to produce a PDP. (Details of phosphor firing step, frit calcination step, sealing step) The phosphor firing step, frit calcination step, and sealing step will be described in detail below.

FIG. 3 is a diagram schematically showing the configuration of a belt-type heating device used in the present embodiment for firing and calcination of the phosphor. The heating device 40 includes a heating furnace 41 for heating the substrate, a conveyor belt 42 for conveying the panel substrate so as to pass through the heating furnace 41, a gas introduction pipe 43 for introducing an atmospheric gas into the heating furnace 41, and the like. Cage,
In the heating furnace 41, a plurality of heaters (not shown) are installed along the transport direction.

The inlet 44 of the heating furnace 41 is connected to each heater.
The substrate can be fired with an arbitrary temperature profile by setting the temperature of each part from the outlet to the outlet 45, and by introducing the atmospheric gas from the gas introducing pipe 43, the inside of the heating furnace 41 can be controlled. It can be filled with atmospheric gas. When sending dry air as atmospheric gas, a gas dryer (not shown) that cools the air to a low temperature (minus several tens of degrees) to condense water
Dry air can be generated by reducing the amount of water vapor in the air (water vapor partial pressure) via

At the time of firing the phosphor, the heating device 40 is used to remove the rear glass substrate 21 having the phosphor layer 25 formed thereon.
Bake in dry air (peak temperature 520 ° C., 10 minutes). As described above, when the phosphor is fired while the dry gas is allowed to flow, the thermal deterioration due to the water vapor in the atmosphere during the phosphor firing can be suppressed. The lower the steam partial pressure in the dry air used at this time, the greater the effect of suppressing the thermal deterioration of the phosphor. That is, it is desirable that the water vapor partial pressure be 15 Torr or less.
10 Torr or less, 5 Torr or less, 1 Torr, 0.
The effect becomes more remarkable as it becomes lower than 1 Torr.

Since there is a certain relationship between the partial pressure of water vapor and the dew point temperature, the "dew point temperature" of water in dry air is
In other words, the lower the dew point temperature is set,
It is preferable to suppress thermal deterioration during the firing of the phosphor, and the dew point temperature of the drying gas is preferably 20 ° C. or lower, 0 ° C. or lower,
It can be said that it is more preferable to set the temperature to −20 ° C. or lower and −40 ° C. or lower.

At the time of frit calcination, the front glass substrate 11 or the rear glass substrate 21 having the sealing glass layer formed thereon is fired in dry air using the heating device 40 (peak temperature 350 ° C., 30 minutes). Also in this calcination step, it is desirable that the dry air introduced into the heating furnace 41 has a water vapor partial pressure of 15 Torr or less, and a water vapor partial pressure of 10 Torr.
r or less, 5 Torr or less, 1 Torr, 0.1 Torr
The lower the value is set, the more the thermal deterioration of the phosphor can be suppressed. That is, the dew point temperature of the dry air is preferably 20 ° C. or lower, more preferably 0 ° C. or lower, −20 ° C. or lower, and −40 ° C. or lower.

FIG. 4 is a diagram schematically showing the structure of the sealing heating device. The heating apparatus for sealing 50 includes a heating furnace 51 for heating the substrates (the front panel substrate 10 and the rear panel substrate 20 which are stacked in this case) housed inside.
And a pipe 52a for sending the atmospheric gas from the outside of the heating furnace 51 to the internal space between the panel substrates 10 and 20, and a pipe 52b for discharging the atmospheric gas from the internal space to the outside of the heating furnace 51. A gas supply source 53 that feeds dry air as an atmospheric gas is connected to the pipe 52a, and a vacuum pump 54 is connected to the pipe 52b. Further, the pipes 52a and 52b are provided with adjusting valves 55a and 55b for adjusting the flow rate of gas passing therethrough.

Using this sealing heating device 50, the sealing step is performed as follows. The rear panel substrate 20 has a vent hole 21a and a vent hole 21 on the outer peripheral portion outside the display area.
b is provided, and glass tubes 26a and 26b are attached to these vents 21a and 21b. In addition, in FIG. 4, the partition walls and the phosphors in the rear panel substrate 20 are omitted.

Front panel substrate 10 and rear panel substrate 20
While being aligned, the sealing glass layer 15 is superposed so as to be interposed between both substrates, and is put in the heating furnace 51. It is preferable that the front panel substrate 10 and the rear panel substrate 20 aligned here are clamped by a clamp or the like so as not to be displaced. Then, the glass tubes 26a and 26b are connected to the pipes 52a and 52b inserted from the outside of the heating furnace 51, and the pipe 52b is evacuated by the vacuum pump 54 to once evacuate the internal space, and then the vacuum pump 54 The dry air is sent through the pipe 52a at a constant flow rate without being used. As a result, dry air circulates in the internal space between the panel substrates 10 and 20 and is discharged from the pipe 52b.

In this way, both panel substrates 10 and 20 are heated while flowing the dry air (3 at the peak temperature of 450 ° C.).
By heating for 0 minutes), the sealing glass layer 15 is softened to seal both panel substrates 10 and 20. When the sealing is completed, one of the glass tubes 26a and 26b is sealed, and a vacuum pump is connected to the remaining glass tubes in the next evacuation step. Next, in the process of filling the discharge gas, a cylinder containing the discharge gas is connected to the remaining glass tube, and the discharge gas is filled in the internal space while operating the exhaust device.

(Effects of the manufacturing method of this embodiment) According to the sealing method of this embodiment, the following effects are obtained as compared with the conventional sealing method. Usually, gases such as water vapor are adsorbed on the front panel substrate and the rear panel substrate, but when these substrates are heated and heated, the adsorbed gas is released.

In the conventional general manufacturing method, after the calcination step, in the sealing step, the front panel substrate and the rear panel substrate are superposed at room temperature and then heated and heated for sealing.
During this sealing process, the gas adsorbed on the front panel substrate and the rear panel substrate is released. In the calcination process,
Even if the gas adsorbed on the substrate escapes to some extent, the gas is adsorbed again by bringing the temperature to room temperature in the atmosphere until the start of the sealing process, so that the gas is released in the sealing process. Then, the released gas is confined in the narrow internal space. At this time, it is known from the measurement result that the partial pressure of water vapor in the internal space is usually 20 Torr or more.

Therefore, the phosphor layer 25 facing the internal space is likely to be thermally deteriorated by the influence of gas (in particular, the influence of water vapor emitted from the protective layer 14). When the phosphor layer (particularly the blue phosphor layer) is thermally deteriorated, the emission intensity is reduced. On the other hand, as in the present embodiment, when dry air is circulated in the internal space during heating and the steam generated in the internal space is continuously discharged to the outside, thermal deterioration of the phosphor layer due to steam is caused. It can be suppressed.

Also in this sealing step, it is desirable that the dry air flowing through the internal space has a water vapor partial pressure of 15 Torr or less, and a water vapor partial pressure of 10 Torr or less and 5 Torr or less, as in the phosphor firing step. 1 To
The lower the value of rr is set to 0.1 Torr or less, the more the thermal deterioration of the phosphor can be suppressed. That is, the dew point temperature of the dry air is preferably 20 ° C. or lower, and 0 ° C. or lower, −20.
It is more preferable that the temperature is not higher than -40 ° C.

(Consideration on Water Vapor Partial Pressure in Atmosphere Gas) By reducing the water vapor partial pressure in the atmosphere gas, it is possible to prevent thermal deterioration due to heating of the blue phosphor as follows. 5 and 6 show the relative emission intensity and chromaticity coordinate y when the blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu) was fired in the air with various partial pressures of water vapor. Is the measurement result. As the firing conditions, the peak temperature was 450 ° C., and the time for maintaining the peak temperature was 20 minutes.

The relative luminescence intensity shown in FIG. 5 is obtained by measuring the luminescence intensity measurement value and the luminescence intensity measurement value of the blue phosphor before firing as a reference value 1.
This is represented by a relative value when 00 is set. The emission intensity is obtained by measuring the emission spectrum from the phosphor layer using a spectrophotometer, calculating the chromaticity coordinate y value from this measurement value, and measuring the chromaticity coordinate y value and the luminance value previously measured with a luminance meter. And the value calculated from the equation (emission intensity = luminance / chromaticity coordinate y value).

The chromaticity coordinate y of the blue phosphor before firing
Was 0.052. From the results of FIGS. 5 and 6, when the water vapor partial pressure is near 0 Torr, no decrease in emission intensity and no change in chromaticity due to heating are observed, but as the water vapor partial pressure increases, the relative blue emission intensity decreases. It can be seen that the chromaticity coordinate y of blue is large.

By the way, a blue phosphor (BaMgAl ₁₀ O
₍₁₇ : Eu) causes the emission intensity to deteriorate and the chromaticity coordinate y value to increase because the activator Eu ²⁺ ion is oxidized by heating and becomes Eu ³⁺ ion. It has been conventionally considered that there is (J. Electr
ochem. Soc. Vol. 145, no. 11,
(November 1998) and the above-mentioned result that the y value of the chromaticity coordinate of the blue phosphor depends on the partial pressure of water vapor in the atmosphere, the Eu ²⁺ ions and oxygen in the gas atmosphere (for example, air) are considered. It is considered that the reaction relating to the deterioration is promoted by the water vapor in the gas atmosphere instead of directly reacting.

Incidentally, the blue phosphor (BaMgAl) was changed in the same manner as above by changing the heating temperature variously.
_{When the} degree of decrease in emission intensity due to the heat of ₁₀ O ₁₇ : Eu) and the change in the chromaticity coordinate y were examined, it was found that in the heating temperature range of 300 to 600 ° C., the higher the heating temperature, the lower the emission intensity due to heat. It was observed that the higher the water vapor partial pressure, the greater the decrease in emission intensity at any heating temperature. On the other hand, there was a tendency that the higher the water vapor partial pressure, the greater the change in the chromaticity coordinate y due to heat.
No tendency was found that the degree of change in the chromaticity coordinate y depends on the heating temperature.

Further, the front glass substrate 11 and the display electrode 1
2, dielectric layer 13, protective layer 14, rear glass substrate 21,
When the amount of water vapor released when each member forming the address electrode 22, the dielectric layer 23, the partition wall 24, and the phosphor layer 25 was heated, the amount of water vapor released from MgO, which is the material of the protective layer 14, was the highest. . Therefore, the main cause of the thermal deterioration of the phosphor layer 25 at the time of sealing is the protective layer 14
It is assumed that water vapor is released from (MgO).

(Modification of this Embodiment) In this embodiment, a fixed amount of dry air is flown into the internal space in the sealing process, but the dry air is introduced after the internal space is evacuated. By repeating the operation alternately,
Water vapor generated in the internal space can be efficiently discharged, and thermal deterioration of the phosphor layer can be suppressed.

Further, even if all of the phosphor firing step, the calcination step and the sealing step are not performed in the dry gas dry gas atmosphere, only one or two of them are performed in the dry gas atmosphere. By doing so, some effect can be obtained. Further, in the present embodiment, in the sealing step, dry air was flown as an atmospheric gas in the internal space,
The same effect can be obtained by flowing an inert gas such as nitrogen which does not react with the phosphor layer and has a low water vapor partial pressure.

Further, in this embodiment, in the sealing step, the dry air is forcedly fed from the glass tube 26a into the inner space between the panel substrates 10 and 20 for sealing. Even without sending dry air, for example, by using the heating device 40 shown in FIG. 3 to seal both panel substrates 10 and 20 in a dry air atmosphere,
Since the dry gas flows into the internal space to some extent from the ventilation holes 21a and 21b, some effect can be obtained.

Although not described in this embodiment,
In addition to this, the front panel substrate 10 on which the protective layer 14 is formed
The amount of water adsorbed on the protective layer 14 is also reduced by firing the product in a dry gas atmosphere, so that thermal deterioration of the blue phosphor layer in the sealing step can be suppressed to some extent. Further, if the firing of the front panel substrate 10 in such a dry gas atmosphere is combined with the manufacturing method of this embodiment, a further effect can be expected.

The PD prepared by the manufacturing method of the present embodiment
Since P also contains a small amount of water in the phosphor layer, P
It is also possible to obtain an effect that there is little abnormal discharge during DP driving. (Example 1)

[0063]

[Table 1]

Panel No. Reference numerals 1 to 4 are PDPs according to the examples produced based on the present embodiment, and the vapor partial pressure of the dry air flowing in the phosphor firing step, the frit calcination step, and the sealing step is set to 0 to 12 Torr. The values are changed to various values within the range. In addition, the panel No. 5 is
In the PDP according to the comparative example, the phosphor firing step, the frit calcination step, and the sealing step are performed with undried air (steam partial pressure 2
It was carried out in 0 Torr).

In each of these PDPs, the thickness of the phosphor layer was 30 μm, and the discharge gas was Ne (95%)-Xe.
(5%) was sealed at 500 Torr. <Luminescence characteristic test> Test method and result: For each of these PDPs, as the luminescence characteristics, when the panel brightness and color temperature (blue cell, red cell, green cell) with white balance without color correction were lit with the same power. And the peak intensity ratio of the emission spectrum when the blue cell and the green cell were made to emit light with the same electric power.

The results of these measurements are shown in Table 1. It should be noted that each PDP produced was disassembled, and the back panel substrate was irradiated with vacuum ultraviolet rays (center wavelength 146 nm) using a krypton excimer lamp to emit light of all colors of blue, green, and red, and When the peak intensity ratio of the emission spectrum when emitting blue light and green light was measured, the same result as the above lighting result was obtained because the manufactured front panel substrate was not provided with a color filter or the like.

Further, take out the blue phosphor from the panel,
The number of H ₂ O gas molecules desorbed from 1 g of the blue phosphor was measured by TDS analysis (thermal desorption gas mass spectrometry).
In addition, the a-axis length and c of the blue phosphor crystal were determined by X-ray diffraction.
The axial length was also measured. In TDS analysis, Japan Vacuum Technology Co., Ltd.
The measurement was carried out as follows using an infrared heating type thermal desorption gas mass spectrometer manufactured by K.K.

The phosphor material packed in the Ta dish was evacuated to the order of 10 ^-4 Pa in the preliminary exhaust chamber, and then inserted into the measuring chamber,
It was evacuated to the order of 10 ⁻⁷ Pa. Then, using an infrared heater, the temperature rising rate from room temperature to 1100 ° C was 10 ° C /
The number of H ₂ O molecules (mass number 18) desorbed from the phosphor was measured in a scan mode with a measurement interval of 15 seconds while the temperature was raised at min. 7 (a), (b) and (c) show panel No. It is a chart which shows the result of having measured about the blue fluorescent substance taken out from 2,4,5.

In the chart of FIG. 7, peaks of the number of H ₂ O molecules desorbed from the blue phosphor can be seen near 100 to 200 ° C. and around 400 to 600 ° C. 100-200
The peak near ℃ is the desorption of the physical adsorption gas, 400
The peak around ˜600 ° C. is considered to be due to desorption of the chemisorption gas. In Table 1, the peak value of the number of molecules of desorbed H ₂ O appearing in the region of 200 ° C. or higher, that is, 400 to
The measurement results of the peak value of the number of desorbed H ₂ O molecules near 600 ° C. and the ratio of the c-axis length to the a-axis length of the blue phosphor crystal are also shown.

Discussion: In the measurement results of Table 1, Examples (Panel Nos. 1 to 4) and Comparative Examples (Panel No. 5)
When the light emission characteristics are compared with respect to and, the light emission characteristics of the example are superior to those of the comparative example (the panel brightness is high and the color temperature is high). Panel No. Comparing the light emitting characteristics of Nos. 1 to 4, panel No. The emission characteristics are improved in the order of 1, 2, 3, 4.

From these results, it can be seen that the lower the water vapor partial pressure in the phosphor firing step, the frit calcination step, and the sealing step, the better the light emission characteristics (panel brightness, color temperature). The emission characteristics are improved by reducing the water vapor partial pressure in this way because the blue phosphor layer (BaMgAl ₁₀ O ₁₇ : Eu) is used.
It is considered that this is because the thermal deterioration of No. 1 is prevented and the value of the chromaticity coordinate y becomes small.

Further, in the blue phosphor of this example, the peak value of the number of desorbed H ₂ O molecules appearing in the region of 200 ° C. or higher in the temperature programmed desorption gas mass spectrometry was 1 × 10 ¹⁶ / g or less. However, the ratio of the c-axis length to the a-axis length is 4.0218 or less, whereas the blue phosphor of the comparative example shows values larger than the above respective values. [Second Embodiment] The PDP of the present embodiment has the same configuration as the PDP of the first embodiment shown in FIG.

The manufacturing method of the PDP is also the same as that of the first embodiment, but there are differences in the opening position of the ventilation hole in the outer peripheral portion of the rear glass substrate 21, the form of applying the sealing glass frit, and the like. . That is, in the PDP manufacturing process, in the sealing process, compared with the phosphor firing process and the frit calcination process, the protective layer on the front plate during heating,
In consideration of the fact that the gas containing water vapor generated from the phosphor layer, the glass for sealing, etc. is confined in the narrow internal space partitioned by the partition walls, the phosphor layer is more susceptible to thermal deterioration, and the present embodiment Then, in the sealing step, the dry air introduced into the internal space was devised so as to flow stably in the space between the partition walls, and the gas generated in the space between the partition walls was efficiently discharged, so that the phosphor layer The effect of preventing thermal deterioration of is enhanced.

8 to 16 are views showing a specific example of the opening position of the vent hole in the outer peripheral portion of the rear glass substrate 21 and the form of applying the sealing glass frit. It should be noted that the rear panel substrate 20 is provided with stripe-shaped partition walls 24 over the entire image display region, but in FIGS. 8 to 16, only a few partition walls 24 on both sides are displayed and the center wall is shown. The partition wall 24 is not shown.

As shown in these figures, a frame-shaped sealing glass region 60 (region where the sealing glass layer 15 is arranged) is set on the outer peripheral portion of the rear glass substrate 21. The sealing glass region 60 is formed on the outermost partition wall 2
4 and a pair of vertical sealing regions 61 extending in the width direction of the partition wall 24. Then, at the time of sealing, the dry air flows through the gaps 65 between the partition walls 24.

The features of the example shown in each drawing will be described below. In the example shown in FIGS. 8 to 12, the sealing glass region 60 is used.
Vents 21a and vents 21 at diagonal positions inside the
b is opened, and during sealing, the dry air introduced from the vent 21a as shown in FIG.
After passing through the gap 63a between the partition wall 4a and the lateral sealing region 62 and being distributed to each gap 65 between the partition walls 24 and flowing therethrough, the gap 63b between the partition end 24b and the horizontal sealing region 62 is formed. It passes through and is discharged from the vent 21b.

In the example shown in FIG. 8, a gap 63a between the horizontal sealing region 62 and the partition end 24a and a gap 63b between the horizontal sealing region 62 and the partition end 24b are adjacent to the vertical sealing region 61. It is set to be wider than the gap 64a and the gap 64b with the partition wall 24 (the minimum width of the gap 63a is D1, the minimum width of the gap 63b is D2, the minimum width of the gap 64a is d1, the gap 6).
If the minimum width of 4b is d2, D1, D2> d1, d2 are set).

With this configuration, the gas flow resistance when the dry air introduced from the ventilation port 21a flows through the gap 65 between the partition walls 24 is smaller than the gas flow resistance when flowing through the gap 64a and the gap 64b. Therefore, the dry air easily spreads in the gaps 63a and 63b, and the dry air is stably distributed to the gaps 65 and flows therethrough. Therefore, the gas generated in each gap 65 is efficiently discharged, and the effect of preventing thermal deterioration of the phosphor layer in the sealing step is enhanced.

Further, the minimum width D1 of the gap 63a and the minimum width D2 of the gap 63b are made twice or three times as large as the minimum width d1 of the gap 64a and the minimum width d2 of the gap 64b. The gas flow resistance when flowing through the gaps 65 between 24 becomes small, and the dry air flows more stably through the gaps 65, so the effect also becomes large. In the example shown in FIG. 9, the vertical sealing region 61 has the partition wall 24 adjacent to it.
, And the minimum width d1 of the gap 64a and the minimum width d2 of the gap 64b are 0. in this case,
Since the dry air does not flow through the gaps 64a and 64b, the dry air is more stably distributed to the gaps 65.

In the example shown in FIGS. 10 to 16, a flow stop partition wall 70 is provided along the inner circumference of the sealing glass region 60. The baffle partition 70 has a frame shape composed of a vertical baffle 71 along the vertical sealing area 61 and a horizontal baffle 72 along the horizontal sealing area 62, and the vents 21a and 21b are provided in the baffle partition 7 respectively.
It is adjacent to the inside of 0 (however, in the example shown in FIG. 12,
There is no vertical partition wall 71, and only the horizontal partition wall 72 is provided. ).

The flow stop partition wall 70 is formed of the same shape and material as the partition wall 24.
The baffle partition 70 can also be formed together when forming. The flow stop partition wall 70 prevents the sealing glass disposed in the sealing glass region 60 from flowing into the display region at the center of the panel when it is heated and softened.

In the example shown in FIG. 10, the gap 63a between the horizontal partition 72 and the partition end 24a and the gap 63b between the horizontal partition 72 and the partition end 24b are the same as in the case of FIG.
1 and the partition wall 24 adjacent to the partition wall 64a and the gap 6
It is set wider than 4b (D1, D2> d1, d
2), the same effect as in the case of FIG. 8 is obtained. In the example shown in FIG. 11, a partition wall 73a and a partition wall 73b for partitioning the gap 64a and the gap 64b between the vertical partition 71 and the partition 24 adjacent thereto are further provided. This partition wall 73
Since the vertical partition wall 71 and the partition wall 24 adjacent to the vertical partition wall 71 are partitioned by a and 73b in the central portion,
As in the case of, the minimum width d1 of the gap 64a and the gap 64
The minimum width d2 of b is 0. Therefore, the same effect as in the case of FIG. 9 is obtained.

In the example shown in FIG. 12, as in the case of FIG. 9, the vertical sealing region 61 is in contact with the partition wall 24 adjacent thereto at the central portion, and the minimum width d1 of the gap 64a and the gap 64b. Since the minimum width d2 is 0, the same effect as in the case of FIG. 9 is obtained. In the example shown in FIG. 13, the positions of the vent holes 21a and 21b inside the baffle partition wall 70 are provided not adjacent to each other but in the vicinity of the center of the vertical partition wall 71, and the gaps 64a and 64b are formed. Partition wall 73a and partition wall 73 that partition the gap at the end
b is provided. In this case, the dry air circulates as in the case of FIG. 11 and has the same effect as in the case of FIG.

The example shown in FIG. 14 is substantially the same as the example shown in FIG. 11, except that the gas inlet vent holes 21a and the gas vent vent holes 21b are formed in two places each and have a stripe shape. Among the plurality of partition walls 24 arranged side by side, the central partition wall 27 located at the center is extended so as to be connected to the horizontal partition wall 72. In this case, the dry air flows separately in each of the two regions divided by the central partition wall 27, but the gap 63a and the gap 63b become the gap 64.
Since it is set wider than a and the gap 64b,
The same effect as the case of 1 is produced. Further, in the example of FIG. 14, it is also possible to adjust the flow rate of dry air for each of the two regions.

(Modification of this Embodiment) In this embodiment, the dry air flowing in the internal space in the sealing step has a water vapor partial pressure of 15 Torr or less (or a dew point temperature of 20 ° C.).
The following points are preferable, and the gas to be flown in the sealing step is not limited to dry air, but an inert gas such as nitrogen which does not react with the phosphor layer and has a low water vapor partial pressure can be used. However, the same effects can be obtained as described in the first embodiment.

Further, although the case where the partition wall is provided on the rear panel substrate side has been described in the present embodiment, the same effect can be obtained also when the partition wall is provided on the front panel substrate side. Play. (Example 2)

[0087]

[Table 2]

Panel No. The PDP No. 6 is a PDP manufactured based on the example of FIG. 10 in the present embodiment, and the steam partial pressure of the dry air flowing in the sealing step is 2 Torr.
(Dew point temperature −10 ° C.). Panel No. 7 PDP
15, the rear panel substrate 20 has a gap 63a between the horizontal partition 72 and the partition end 24a and a horizontal partition 72 as shown in FIG.
The gap 63b between the partition wall end portion 24b and the partition wall end portion 24b is set to be narrower than the gap 64a and the gap 64b between the vertical partition wall 71 and the partition wall 24 adjacent thereto (D1, D2 <d1, d2). It is similar to the example shown in. This panel No.
No. 7 is the panel No. It is a PDP manufactured by sealing under the same conditions as in No. 6.

Panel No. In the PDP No. 8 as shown in FIG. 16, the back panel substrate 20 is provided with only one vent hole 21a. This panel No. 8 is related to the comparative example, and in the sealing step, the front panel substrate 1
0 and the rear panel substrate 20 are superposed and then heated and heated to seal the inner space without flowing dry air.

These panel No. In PDPs 6 to 8, the manufacturing process was the same except the sealing process. The panel structure is the same except for the vent hole and the partition wall for blocking the flow, the phosphor film thickness is 30 μm, and the discharge gas is Ne.
(95%)-Xe (5%) was encapsulated at 500 Torr. <Light emission characteristic test> Test method and result: For each of these PDPs, as the light emission characteristics, the panel luminance and color temperature in white balance without color correction, and the light emission spectrum when the blue cell and the green cell were made to emit light at the same power The peak intensity ratio was measured.

The results of these measurements are shown in Table 2. In addition, each PDP produced was disassembled, and the rear panel substrate was irradiated with vacuum ultraviolet rays using a krypton excimer lamp to emit light of all colors, and emission spectra of blue and green. When the peak intensity ratio was measured, the same result as that obtained by the above lighting was obtained.

Further, take out the blue phosphor from the panel,
The number of H ₂ O gas molecules desorbed from 1 g of the blue phosphor at 200 ° C. or higher was measured by the TDS analysis method. The ratio of the c-axis length to the a-axis length of the blue phosphor crystal was also measured by X-ray diffraction. Table 2 also shows these results. Discussion: In the measurement results of Table 2, the panel No. No. 6 shows the best light emission characteristic.

Panel No. The light emission characteristics of panel No. 6 are panel No.
Panel No. 7 was better than the emission characteristics of No. 7. In No. 6, in the sealing step, the dry air stably flowed through the space between the partition walls, and the gas generated inside could be efficiently discharged, while the panel No. In No. 7, most of the dry air introduced from the ventilation port 21a was discharged from the ventilation port 21b through the gaps 63a and 63b and did not flow so much into the gap 65 between the partition walls, so the gas generated in the gap 65 was removed. It is considered that the reason was that it could not be efficiently discharged.

Further, the panel No. It is considered that the light emission characteristics of No. 8 are poor because the dry gas does not flow into the gap 65 and the gas generated in the gap 65 is not discharged. Although the PDP based on FIG. 10 has been described in this embodiment,
In the PDP based on any of FIGS. 10 to 16, almost the same good emission characteristics were obtained. [Third Embodiment] The PDP of the present embodiment has the same configuration as the PDP of the first embodiment shown in FIG.

The manufacturing method of the PDP is the same as that of the first embodiment, but when the front panel substrate 10 and the rear panel substrate 20 are sealed in the sealing step,
Heating is performed while flowing dry air while adjusting the internal space to a pressure lower than atmospheric pressure. That is, a glass frit for sealing is applied to at least one of the front panel substrate 10 and the rear panel substrate 20 to form a sealing glass layer,
Calcine. After calcination, both substrates 10 and 20 are superposed, and the superposed substrates 10 and 20 are put into the heating furnace 51 of the heating apparatus for sealing 50 shown in FIG.
6a and 26b are connected to the pipes 52a and 52b, and the pipe 52
The dry air from the gas supply source 53 is sent at a constant flow rate through the pipe 52a while the internal space is depressurized by exhausting from the b through the vacuum pump 54. At this time,
The adjusting valves 55a and 55b are adjusted so that the internal space is maintained at a predetermined pressure lower than the atmospheric pressure.

As described above, both panel substrates 10 and 20 are heated and heated while flowing dry air in the internal space under reduced pressure,
By heating at the sealing temperature (peak temperature 450 ° C.) for 30 minutes, the sealing glass layer 15 is softened and both panel substrates 10 and 20 are sealed. Then, the panel is fired while evacuating the internal space of the attached panel substrate (35).
3 hours at 0 ° C). Then, a discharge gas having the above composition is sealed at a predetermined pressure to produce a PDP.

(Effects of the Present Embodiment) In the sealing step of the present embodiment, as in the case of the first embodiment, the sealing is performed while the dry gas is allowed to flow in the internal space. The thermal deterioration due to contact with is suppressed. The vapor partial pressure of the dry air flowing in the internal space is preferably 15 Torr or less, as in the first embodiment, and the vapor partial pressure is 10 Torr.
The lower the temperature is set to 5 Torr or less, 1 Torr, 0.1 Torr or less, the more the thermal deterioration of the phosphor can be suppressed, and the dew point temperature of the dry air is preferably 20 ° C. or less, 0 ° C. or less, -20 ℃ or less, -40 ℃
The following is more preferable.

Further, in this embodiment, since the sealing is performed while keeping the internal space at a pressure lower than the atmospheric pressure, the steam generated in the internal space is discharged to the outside more efficiently than in the first embodiment. To be done. Further, since the dry air is introduced while maintaining the internal space at atmospheric pressure or lower, the front panel substrate 10 and the rear panel substrate 20 can be sealed with good adhesion without the internal space expanding during sealing.

The lower the pressure of the internal space at the time of sealing is, the more preferable it is because the partial pressure of water vapor can be easily lowered and the sealing can be performed with good adhesion. At this point, the pressure in the internal space is 5
It is preferable to set below 00 Torr, 300T
It is more preferable to set it to or or less. On the other hand, when flowing dry air, if the pressure is too low, the oxygen partial pressure of the atmospheric gas will be low. Therefore, BaMgAl ₁₀ O ₁₇ : Eu and Zn ₂ SiO ₄ : M which are often used in PDPs.
When oxide-based phosphors such as n and Y ₂ O ₃ : Eu are heated in an oxygen-free atmosphere, defects such as oxygen defects are formed, and the luminous efficiency is likely to decrease. Therefore, from this point of view, it can be said that it is preferable to set the pressure to 300 Torr or more.

(Modification of this Embodiment) In the present embodiment, in the sealing step, dry air was flown as an atmosphere gas in the internal space, but oxygen, nitrogen, etc. which do not react with the phosphor layer The same effect can be obtained by flowing an inert gas having a low water vapor partial pressure. However, it is preferable to flow an atmosphere gas containing oxygen because luminance deterioration can be suppressed.

Further, in the present embodiment, the internal space is depressurized from the low temperature when the sealing glass is not softened. In this case, the front panel substrate 10 and the rear panel substrate 2 are
Since the gas in the heating furnace 51 may flow into the internal space through the gap between the heating furnace 51 and 0, it is preferable to fill or flow dry air also in the heating furnace 51. Further, in the sealing step, in order to prevent the gas in the heating furnace 51 from flowing into the internal space, the dry gas is not forcibly discharged from the internal space at a low temperature when the sealing glass is not softened, and a large amount of gas is not generated. The internal space may be kept close to the atmospheric pressure, and after the temperature rises to some extent, the internal space may be forcibly discharged to lower the internal space below the atmospheric pressure. In this case, the temperature at which exhaust starts is
It is desirable that the temperature is equal to or higher than the temperature at which the sealing glass begins to soften. From this point of view, the temperature at which exhaust is started is preferably 300 ° C. or higher, more preferably 350 ° C. or higher, and further preferably 400 ° C. or higher.

Further, in the present embodiment, the sealing process is described as being performed while flowing the dry air while keeping the internal space in the reduced pressure state. However, the phosphor firing process and the calcination process are also performed in the reduced pressure state under the dry air condition. It is also possible to carry out in a flowing atmosphere, and the same effect is obtained. Also in this embodiment, it is more effective if the panel structure as described in the second embodiment is applied.

(Example 3)

[0104]

[Table 3]

Table 3 shows manufacturing conditions for the PDP according to the example manufactured based on the present embodiment and the first embodiment and the PDP according to the comparative example. Panel No. 11-
21 is a PDP based on this embodiment,
The water vapor partial pressure of the dry gas flowing inside the panel in the sealing step, the gas pressure of the panel internal space, the temperature at which the panel internal space starts to be below atmospheric pressure, and the type of the dry gas are changed.

Panel No. The PDP No. 22 is the PDP according to the first embodiment, and the dry air was introduced into the internal space in the sealing step, but the exhaust was not forcibly performed. The PDP of panel No. 23 is the PDP according to the comparative example, which was manufactured by the conventional method in the sealing step without introducing dry gas into the internal space.

In each of these PDPs, the thickness of the phosphor layer was 30 μm, and the discharge gas was Ne (95%)-Xe.
(5%) was sealed at 500 Torr. <Luminescence Characteristic Test> Test Method and Results For each of these PDPs, the relative luminous intensity of blue light emission, the value of the chromaticity coordinate y of blue light emission, the peak wavelength of blue light emission, and the white display (without color correction) were used as the light emission characteristics. The peak intensity ratio of the emission spectrum when the color temperature, the blue cell and the green cell were made to emit light with the same power was measured.

The blue emission intensity, the value of the chromaticity coordinate y of blue emission, and the color temperature of white display (without color correction) were measured by the method described in the first embodiment. The peak wavelength of blue light emission was determined by turning on only the blue cell and measuring the emission spectrum. The measurement results are shown in Table 3. The relative emission intensities of blue emission shown in Table 3 are obtained by comparing the emission intensity measured values with the panel No. 1 according to the comparative example. 23 is a relative value when the emission intensity measurement value for 23 is set to a reference value of 100.

Further, each PDP produced was disassembled, and the rear panel substrate was irradiated with vacuum ultraviolet rays using a krypton excimer lamp to obtain chromaticity coordinates y when emitting blue light, color temperature when emitting all colors, and When the peak intensity ratio of the emission spectrum when emitting blue and green light was measured,
The same result as the result of the above lighting was obtained. Further, the blue phosphor was taken out from the panel, and the number of H ₂ O gas molecules desorbed from 1 g of the blue phosphor at 200 ° C. or higher was measured by TDS analysis. The ratio of the c-axis length to the a-axis length of the blue phosphor crystal was also measured by X-ray diffraction. Table 3 shows
These results are also shown.

Consideration: Example (Panel Nos. 11 to 21)
And the comparative example (panel No. 23) are compared with each other in terms of light emitting characteristics, the example shows superior light emitting characteristics to the comparative example (higher emission intensity of blue light emission and higher color temperature of white display). Comparing the light emission characteristics of panel No. 14 and panel No. 22, the same value is shown. This shows that if the vapor partial pressure of the dry air flowing in the internal space is the same, the same effect (light emission characteristics) can be obtained whether the internal space is at atmospheric pressure or at reduced pressure. There is.

However, in Panel No. 22, there were some in which a gap was seen between the partition wall and the front panel substrate. It is considered that this is because in Panel No. 22, the internal space swelled to some extent by the dry gas introduced during sealing.
Comparing the light emission characteristics of panel Nos. 11 to 14, No.
It can be seen that the blue emission intensity is high and the chromaticity coordinate y of blue emission is also small in the order of 11 to 14. From this, it is understood that the lower the water vapor partial pressure of the dry air, the higher the blue light emission intensity and the smaller the chromaticity coordinate y of the blue light emission. It is considered that this is because the heat deterioration of the blue phosphor was prevented by reducing the water vapor partial pressure.

Comparing the light emission characteristics of Panel Nos. 14 to 16, it is shown that the chromaticity coordinate y of blue light emission is the same and that the chromaticity coordinate y of blue light emission is not affected by the pressure of the internal space. . On the other hand, the relative emission intensity of blue emission decreases in the order of Panel Nos. 14-16. This indicates that when the oxygen partial pressure of the atmospheric gas becomes low, defects such as oxygen defects occur in the phosphor, and the emission intensity of blue light emission decreases.

Panel No. 14 and Panel Nos. 20, 2
Comparing the emission characteristics of No. 1 shows that the chromaticity coordinates y of blue light emission are the same and that the chromaticity coordinates y of blue light emission are not affected by the type of dry gas flowing into the internal space.
On the other hand, for the relative emission intensity of blue emission, see panel N
Nos. 20 and 21 are lower than those of Panel No. 14. This is nitrogen and Ne (95%) as dry gas.
This indicates that when a gas that does not contain oxygen, such as -Xe (5%), is used, defects such as oxygen defects occur in the phosphor and the emission intensity decreases.

Panel No. 14 and Panel Nos. 17 to 1
Comparing the light emission characteristics of No. 9, panel No. 17, 18, 1
In the order of 4 and 19, the blue light emission intensity is improved and the chromaticity coordinate y is also decreased. This indicates that the higher the temperature at which the inner space is evacuated and the pressure becomes lower than the atmospheric pressure, the higher the blue emission intensity and the smaller the chromaticity coordinate y become. Therefore, the evacuation start temperature of the inner space should be increased. It is considered that the atmospheric gas around the panel was prevented from flowing into the internal space of the panel.

Further, each panel No. shown in Table 3 Looking at the relationship between the chromaticity coordinate y of the blue light emission and the peak wavelength of the blue light emission in FIG.
It can be seen that the peak wavelength of blue light emission is short. This indicates that the chromaticity coordinate y value of blue emission is small and the peak wavelength of blue emission is short.
[Fourth Embodiment] The PDP of the present embodiment has the same configuration as the PDP of the first embodiment shown in FIG.

In the method for manufacturing a PDP of this embodiment, the conventional method is performed up to the sealing step of sealing the front panel substrate 10 and the rear panel substrate 20 (that is, in the sealing step, After the front panel substrate 10 and the rear panel substrate 20 are superposed on each other, the temperature is raised by heating without flowing dry air into the internal space.) In the exhausting step, a dry gas is flown into the internal space before the vacuum exhaust is started. However, the difference is that the heating treatment is performed, and this makes it possible to restore the emission characteristics of the blue phosphor layer that has been thermally deteriorated by the sealing step.

Hereinafter, the exhaust process in the present embodiment will be described in detail. In the exhaust step of the present embodiment, the same heating device for sealing as shown in FIG.
Will be described with reference to. Glass tubes 26a and 26b are previously attached to the ventilation holes 21a and 21b of the rear panel substrate 20. Piping 52 on the glass tubes 26a and 26b
After connecting the a and 52b and evacuating the pipe 52b with the vacuum pump 54 to temporarily evacuate the internal space, the vacuum pump 54 is not used and the dry air is sent from the pipe 52a at a constant flow rate. As a result, both panel substrates 10
Dry air circulates in the internal space between the 20 and is discharged from the pipe 52b.

In this way, while the dry air is flowing into the internal space, both panel substrates 10 and 20 are heated and heated to a predetermined temperature. After that, the supply of dry air is stopped, and the gas adsorbed inside the panel substrates 10 and 20 is exhausted by maintaining a predetermined exhaust temperature while exhausting using the vacuum pump 54.

After the exhaust process is completed in this way, a discharge gas is filled in to produce a PDP. (Regarding Effects of the Present Embodiment) According to the exhaust process of the present embodiment, there is an effect of preventing thermal deterioration of the phosphor layer in the exhaust process.

In the PDP manufacturing process, a phosphor firing process of applying a phosphor to form a phosphor layer and then firing the phosphor layer, and a process of applying a sealing glass frit and then calcining it In the baking process and the sealing process of overlapping and sealing the front panel substrate and the rear panel substrate, the phosphor layer (especially the blue phosphor) is likely to be thermally deteriorated, but the sealing process before the exhaust process is temporarily performed. Even if the phosphor layer is deteriorated due to heat due to the above conditions and the light emitting characteristic is deteriorated, the light emitting characteristic of the phosphor layer can be recovered.

The reason for this is considered as follows. When the panel substrate sealed by the sealing process is heated and heated,
Gas (especially water vapor) is released into the internal space. For example, if the sealed panel substrate is left to stand in the atmosphere, moisture or the like is also adsorbed inside, so that when it is heated, water vapor or the like is released. Here, according to the exhaust process of the present embodiment, before the vacuum exhaust is started, water vapor or the like is efficiently released by the dry gas treatment of heating and raising the temperature of the panel substrate while circulating the dry air in the internal space. It is discharged to the outside. Therefore, compared with the conventional exhaust process of simply performing vacuum exhaust without performing the dry gas treatment, thermal deterioration is reduced.

Further, it is considered that the gas discharge action by the dry gas treatment causes a reaction opposite to that when the phosphor layer is thermally deteriorated to discharge the gas and restore the light emission characteristics. As described above, in the present embodiment, the light emission characteristics of the blue phosphor that has once been thermally deteriorated can be recovered in the exhaust step which is the final thermal process, so that the practical effect is large.

In order to enhance the effect of recovering the emission characteristics of the blue phosphor in this exhaust step, it is preferable to set the following conditions. The peak temperature in the exhausting process (that is, the higher temperature of the temperature when heating while flowing the drying gas and the temperature when performing vacuum evacuation), the higher the temperature is set, the more the emission characteristics of the blue phosphor are recovered. The effect increases.

In order to obtain a sufficient effect of recovering the emission characteristics,
It is preferable to set the peak temperature (higher temperature among the drying gas treatment temperature and the exhaust gas temperature) to 300 ° C. or higher, and further to 360 ° C., 380 ° C., 400 ° C. or higher. However, it is necessary not to raise the temperature so high that the sealing glass softens and flows out. Further, it is preferable that the temperature for heating and raising in the dry gas treatment is set higher than the exhaust temperature at the time of vacuum exhaust. This is because when the exhaust temperature during vacuum exhaust is higher than the heating temperature during dry gas treatment, the effect is reduced by the gas (especially water vapor) released from the substrate into the internal space during vacuum exhaust, whereas dry gas treatment It is considered that when the heating temperature at this time is higher, the amount of gas released to the internal space during vacuum evacuation decreases.

The steam partial pressure of the dry gas to be circulated in the dry gas treatment is preferably set lower. That is, the effect of recovering the emission characteristics of the blue phosphor is improved as the water vapor partial pressure of the dry gas is lower, but the remarkable effect is exhibited as compared with the conventional vacuum evacuation process.
It is in the range of rr or less. It can be seen from the following experiment that the emission characteristics of the blue phosphor that has been thermally deteriorated can be recovered.

17 and 18 show the blue phosphor (BaM).
(gAl ₁₀ O ₁₇ : Eu) is a characteristic diagram showing the steam partial pressure dependence of the effect of recovering the emission characteristics by re-baking in air after thermally degrading it, which was measured as follows. is there. First, a blue phosphor (with a chromaticity coordinate y value of 0.05
2) was thermally deteriorated by baking (20 minutes at a peak temperature of 450 ° C.) in air having a water vapor partial pressure of 30 Torr. The heat-deteriorated blue phosphor has a chromaticity coordinate y value of 0.
The relative emission intensity was 092 and the relative emission intensity (an index of the emission intensity when the emission intensity of the completely unfired blue phosphor was 100) was 85.

Then, the heat-deteriorated blue phosphor was re-baked at a predetermined peak temperature in air with various values of water vapor partial pressure, and then the relative emission intensity and the chromaticity coordinate y value were measured. The peak temperature during re-baking is 350 ° C.
And 450 ° C., and the peak temperature maintenance time was 30 minutes. FIG. 17 shows the relationship between the partial pressure of water vapor in air and the measured relative luminescence intensity during re-firing, and FIG. 18 shows
The relationship between the partial pressure of water vapor in air and the measured chromaticity coordinate y value during re-firing is shown.

From the characteristic diagrams of FIGS. 17 and 18, the blue relative luminescence intensity is obtained in the case where the re-baking temperature is 350 ° C. or 450 ° C. and the water vapor partial pressure in the air during re-baking is in the range of 0 to 30 Torr. It can be seen that is high and the blue chromaticity coordinate y value is small. This is because even if the blue phosphor is heat-deteriorated by firing in an atmosphere containing a large amount of water vapor and the emission characteristics are deteriorated, the emission characteristics are recovered by re-firing in an atmosphere with a lower water vapor partial pressure. That is, it means that the thermal deterioration of the blue phosphor is a reversible reaction.

It is also understood from the characteristic diagrams of FIGS. 17 and 18 that the lower the water vapor partial pressure in the air during re-firing and the higher the re-firing temperature, the greater the effect of recovering the light emission characteristics. Although detailed description is omitted, in addition to this, the same measurement was performed by changing the time for maintaining at the peak temperature. As a result, it was found that the longer the time of maintaining at the peak temperature, the greater the effect of recovering the light emission characteristics.

(Modification of this Embodiment) In the exhaust process of this embodiment, dry air is used for performing the dry gas treatment, but it can be similarly carried out by using an inert gas such as nitrogen or argon. The same effect can be obtained. Further, in the exhaust step of the present embodiment, before the vacuum exhaust is started, the dry gas treatment for heating and raising the temperature of the panel substrate while circulating the dry air was performed, but the vacuum exhaust is simply performed without performing the dry gas treatment. Even when it is performed, the emission characteristics of the phosphor layer can be restored to some extent by setting the exhaust temperature to a higher exhaust temperature (360 ° C. or higher) than the conventional general exhaust temperature. And, also in this case, the higher the exhaust temperature is set,
A large effect of recovering the light emission characteristic can be obtained.

However, the effect of recovering the emission characteristics of the phosphor layer is greater when the dry gas treatment is performed. It is considered that this is because the inner space is narrow, so that it is difficult to sufficiently exhaust the steam released during vacuum exhaust to the outside of the panel unless the dry gas treatment is performed. Further, in the present embodiment as well, if the panel structure described in the second embodiment is applied, a larger gas discharging effect can be expected during the dry gas treatment.

(Example 4)

[0133]

[Table 4]

Panel No. Reference numerals 21 to 29 are PDPs of the examples produced by performing a dry gas treatment and then vacuum-evacuating based on the present embodiment, and various heating temperatures and exhaust temperatures during the dry gas treatment are set. It was prepared by changing the temperature. In the dry gas treatment, a predetermined heating temperature was maintained for 30 minutes while flowing dry air, and a predetermined exhaust temperature was maintained for 2 hours during vacuum evacuation.

Panel No. Nos. 30 to 32 are PDPs of the examples produced by vacuum evacuation at an exhaust temperature of 360 ° C. or higher without performing the dry gas treatment based on the above modification. Panel No. 33 is a PDP according to a comparative example, which was manufactured by vacuum evacuation for 2 hours while heating at 350 ° C. without performing dry gas treatment, as in the conventional case. In each of these PDPs, the panel structure is the same, and the thickness of the phosphor layer is 30.
The discharge gas was Ne (95%)-Xe (5%) sealed at 500 Torr.

<Light Emission Characteristic Test> For each of these PDPs, the relative light emission intensity of blue light emission and the chromaticity coordinate y value of blue light emission were measured as light emission characteristics. Test results and discussion: These measurement results are as shown in Table 4. In addition, the emission intensity is the panel No. of the comparative example. The emission intensity of 33 is 100, and the relative emission intensity is shown.

Panel No. Nos. 21 to 28 are all panel numbers. 33, the emission intensity is high and the chromaticity coordinate y value of blue emission is small. This is because the PDP is manufactured by using the exhaust process of the present embodiment, so that
It shows that the light emission characteristics of are improved. Panel No.
Comparing the emission characteristics between Nos. 21 to 24, the panel No. Two
The emission characteristics are improved in the order of 1, 22, 23 and 24 (the relative emission intensity is increased and the chromaticity coordinate y value is decreased). This indicates that the higher the heating temperature during the dry gas treatment is set, the more the effect of recovering the emission characteristics of the blue phosphor layer is improved.

Further, the panel No. Comparing the light emission characteristics among 24, 25, and 26, the panel No. 26, 25, 2
In the order of 4, the light emission characteristics are improved. This indicates that the effect of recovering the emission characteristics of the blue phosphor layer is improved by setting the heating temperature during the dry gas treatment higher than the exhaust temperature during vacuum exhaust. In addition, the panel No. 24,
Comparing the light emission characteristics between Nos. 27 to 29, the panel No. Two
The emission characteristics are improved in the order of 7, 28, 24, 29.
This indicates that the smaller the partial pressure of water vapor during the dry gas treatment is set, the more the effect of recovering the emission characteristics of the blue phosphor layer is improved.

In addition, the panel No. Nos. 30 to 32 are panel Nos. Compared with No. 33, the emission intensity is high and the chromaticity coordinate y value of blue emission is small. This indicates that the emission characteristics of the PDP are improved as compared with the conventional case by manufacturing the PDP using the exhaust process of the above modification. However, the panel No. Nos. 30 to 32 are panel Nos. The emission characteristics are inferior to those of 21 and the like. This shows that the effect of recovering the emission characteristics of the blue phosphor layer is greater when the dry gas treatment is performed.

[Embodiment 5] The PDP of this embodiment is
It has the same configuration as the PDP of the first embodiment shown in FIG.
The PDP manufacturing method is the same as that of the first embodiment up to the calcination step, but when the front panel substrate 10 and the rear panel substrate 20 are sealed, the front panel substrate 10 and the rear panel substrate 20 are separated. They differ in that they are preheated in a state where the facing surfaces are open, and are superposed and sealed in a heated state.

In the PDP of this embodiment, the chromaticity coordinate y of the emission color when only the blue cell is turned on is 0.08 or less, and the peak wavelength of the emission spectrum is 455 nm or less.
With white balance without color correction, the color temperature can be set to 7,000K or higher. Further, depending on the manufacturing conditions, by setting the chromaticity coordinate y of blue light emission to 0.06 or less, it is possible to set the color temperature to about 11000K with white balance without color correction.

Hereinafter, the sealing step in this embodiment will be described in detail. FIG. 19: is a figure which shows typically the structure of the sealing device used for a sealing process. This sealing device 80
Is a gas introduction valve 82 for adjusting the introduction amount of the atmospheric gas introduced into the heating furnace 81 to the heating furnace 81 for heating the front panel substrate 10 and the rear panel substrate 20, and the discharge amount of the gas discharged from the heating furnace 81. A gas discharge valve 83 and the like for adjustment are attached and configured.

The inside of the heating furnace 81 can be heated to a high temperature by a heater (not shown). Also, heating furnace 8
Atmosphere gas (for example, dry air) that forms an atmosphere in which the front panel substrate and the rear panel substrate are heated
Can be introduced from the gas introduction valve 82, and exhausted from the gas discharge valve 83 by a vacuum pump (not shown) to heat the furnace 81.
It is also designed to be able to create a high vacuum inside. The degree of vacuum in the heating furnace 81 can be adjusted by the gas introduction valve 82 and the gas discharge valve 83.

A gas dryer (not shown) is provided between the atmospheric gas supply source and the heating furnace 81 to remove the atmospheric gas by cooling it to a low temperature (minus several tens of degrees) to condense water. By passing through this gas dryer, the amount of water vapor in the atmospheric gas (water vapor partial pressure) is reduced. The heating furnace 81 is provided with a mounting table 84 on which the front panel substrate 10 and the rear panel substrate 20 are stacked and mounted. On the mounting table 84, a moving pin for moving the rear panel substrate 20 in parallel is provided. 85 is installed. A pressing mechanism 86 for pressing the rear panel substrate 20 downward is installed above the mounting table 84.

FIG. 20 is a perspective view showing the internal structure of the heating furnace 81. 19 and 20, the rear panel substrate 20 is arranged so that the longitudinal direction of the partition walls is along the lateral direction of the drawing. As shown in FIGS. 19 and 20, the rear panel substrate 20 is set to be slightly longer than the front panel substrate 10 in the longitudinal direction (lateral direction in the drawing) of the partition wall, and both ends of the rear panel substrate 20 are front panel substrates. It protrudes outward from both ends of 10. A lead wire for connecting the address electrode 22 to the drive circuit is provided in this protruding portion. The moving pin 85 and the pressing mechanism 86 are arranged so as to sandwich the protruding portion of the rear panel substrate 20 mounted on the mounting table 84 from above and below near the four corners of the rear panel substrate 20.

The upper ends of the four moving pins 85 project upward from the upper surface of the mounting table 84, and can be simultaneously moved up and down by a pin elevating mechanism (not shown) provided inside the mounting table 84. . Each of the four pressing mechanisms 86 has a cylindrical support portion 86a fixed to the upper portion of the heating furnace 81, a slide rod 86b supported inside the support portion 86a in a vertically movable state, and a support portion. A spring 86 which is inside 86a and biases the slide rod 86b downward.
c, and the lower end of the slide rod 86b presses the rear panel substrate 20 by the urging force of the spring 86c.

FIG. 21 is a diagram showing the operation when the preheating process and the sealing process are performed using this sealing device. The calcination, preheating, and sealing steps will be described with reference to this figure. Calcining step: In advance, the outer peripheral portion of the facing surface of the front panel substrate 10 (the surface facing the rear panel substrate 20) or the outer peripheral portion of the facing surface of the rear panel substrate 20 (the surface facing the front panel substrate 10), or A paste made of glass for sealing (glass frit) is applied to the outer peripheral portions of the facing surfaces of both the front panel substrate 10 and the rear panel substrate 20.
The sealing glass layer 15 is formed by pre-baking at about 10 ° C. for 10 to 30 minutes (the sealing glass layer 15 is formed on the facing surface of the front panel substrate 10 in the figure).

Preheating Step: Then, the front panel substrate 1
0 and the rear panel substrate 20 are aligned with each other and placed in a fixed position on the mounting table 84, and the pressing mechanism 8 is pressed.
6 is set and the rear panel substrate 20 is pressed (see FIG. 21).
(See (a)). Next, the following operation is performed while circulating the atmospheric gas (dry air) in the heating furnace 81 (or while using vacuum exhaust from the gas exhaust valve 83).

The moving pin 85 is raised to push the rear panel substrate 20 upward to move it in parallel (FIG. 21B).
reference). As a result, the gap between the facing surfaces of the front panel substrate 10 and the rear panel substrate 20 is widened, and the rear panel substrate 2
The surface on which the 0 phosphor layer 25 is arranged is opened to a large space in the heating furnace 81. In this state, the gas is released from the panel substrates 10 and 20 by heating and heating the inside of the heating furnace 81. Then, at a predetermined temperature (for example, 400
(° C) is reached, the preheating step is completed.

Sealing step: Subsequently, the moving pin 85 is lowered to re-stack the rear panel substrate 20 on the front panel substrate 10. At this time, the rear panel substrate 20 is overlaid in the original aligned state (FIG. 2).
1 (c)). When the inside of the heating furnace 81 reaches a predetermined sealing temperature (about 450 ° C.) higher than the softening point of the sealing glass layer 15, the sealing temperature is maintained for 10 to 20 minutes. At this time, the outer peripheral portions of the front panel substrate 10 and the rear panel substrate 20 are sealed by the softened sealing glass. During this time, the back panel 20 is pressed by the pressing mechanism 86.
Since it is pressed against the front panel substrate 10, stable sealing can be performed.

When the sealing is completed, the pressing mechanism 86
To release the sealed substrate. After performing the sealing process in this manner, an exhaust process is performed. In this embodiment,
As shown in FIGS. 19 and 20, only one vent hole 21a is provided on the outer peripheral portion of the back panel substrate 20, and a vacuum pump (not shown) is connected to the glass tube 26 attached to the vent hole 21a. Exhaust. After this evacuation step, the discharge gas is sealed from the glass tube 26 into the internal space, the ventilation port 21a is sealed, and the glass tube 26 is cut off to manufacture the PDP.

(Regarding Effects of Manufacturing Method of this Embodiment)
The manufacturing method of the present embodiment has the following effects as compared with the conventional manufacturing method. As described in the first embodiment, in the conventional general manufacturing method, in the sealing step,
Since the released gas is confined in the narrow inner space, the phosphor layer 25 facing the inner space is likely to be thermally deteriorated by the influence of the gas (in particular, the influence of water vapor emitted from the protective layer 14). When the phosphor layer (particularly the blue phosphor layer) is thermally deteriorated, the emission intensity is reduced.

On the other hand, according to the manufacturing method of the present embodiment, gas such as water vapor adsorbed on the front panel substrate 10 and the rear panel substrate 20 is released by preheating. Since a wide gap is formed between 10 and 20, the generated gas is not confined in the internal space. Then, after preheating, since both panel substrates 10 and 20 are sealed in a heated state,
Moisture or the like will not be adsorbed on both panel substrates 10 and 20 after preheating. Therefore, both panel substrates 10 can be sealed.
The gas generated from 20 is reduced, and thermal deterioration of the phosphor layer 25 is prevented.

Further, in the present embodiment, the steps from the preheating step to the sealing step are performed in the atmosphere in which the dry air flows, so that the phosphor layer 25 is formed by the water vapor in the atmosphere gas.
Does not cause thermal deterioration. Further, by using the sealing device 80 as described above, the preheating step and the sealing step can be continuously performed in the same heating furnace 81, so that these steps can be performed quickly and with less energy consumption. It can be carried out.

If the front panel substrate 10 and the rear panel substrate 20 are first aligned and placed using the sealing device 80 as described above, sealing is performed in the aligned state. (Consideration of temperature to be raised by preheating and timing of overlapping front panel substrate and rear panel substrate) The phosphor layer 25 is formed by the gas (water vapor emitted from the protective layer 14) generated from the substrate at the time of sealing. From the viewpoint of preventing thermal deterioration, it can be said that it is better to superpose them after heating to a temperature as high as possible.

To investigate this point in more detail,
The following experiment was conducted. As with the front panel substrate 10, Mg
The amount of water vapor released from the MgO layer was measured with time using a thermal desorption gas mass spectrometer while gradually heating the glass substrate on which the O layer was formed at a constant heating rate. . FIG. 22 shows the measurement results, and shows the amount of released water vapor at each heating temperature up to 700 ° C.

In the graph of FIG. 22, 200 ° C. to 300 ° C.
A first peak is seen in the vicinity, and a second peak is seen around 450 ° C to 500 ° C. From the result of FIG. 22, when the temperature of the protective layer 14 is increased by heating, the value corresponding to the first peak is 2
It is presumed that a large amount of water vapor is released near 00 ° C to 300 ° C, and when the temperature of the protective layer 14 is further increased by heating, a large amount of water vapor is also released near 450 ° C to 500 ° C, which corresponds to the second peak. It

Therefore, at the time of heating and heating in the sealing step,
In order to prevent water vapor released from the protective layer 14 from being trapped in the internal space, the front panel substrate 10 and the rear panel substrate 20 are kept at a temperature of at least about 200 ° C., preferably about 300 ° C. to 400 ° C. It is considered that the temperature should be raised by heating in the separated state. Also, with the front panel substrate 10 and the rear panel substrate 20 separated from each other,
It is considered that if the temperature is raised to a high temperature of about 450 ° C. or higher and the layers are superposed, the gas released from the panel after the superposition is almost completely suppressed. In this case, the phosphor can be sealed in a state where it is hardly thermally deteriorated during sealing, and even after the PDP is completed, water vapor adsorbed in the panel may be gradually released during discharge. Since the number is reduced, it is possible to suppress a change with time after the panel is completed.

However, since the firing temperature for forming the phosphor layer and the MgO protective layer is generally about 520 ° C.,
Exceeding this temperature is not preferred. Therefore, 450
It can be said that it is more preferable to raise the temperature to a high temperature of about 520 to 520 ° C and then stack the layers. On the other hand, when the front panel substrate and the rear panel substrate are separated from each other, if the glass for sealing is heated above the softening point, the glass for sealing may flow out from its original position and stable sealing may not be possible.

Therefore, from the viewpoint of preventing both deterioration of the phosphor layer due to generated gas and stable sealing, the following (1), (2), and (3) are considered. Can be considered. (1) It can be considered that the front panel substrate and the rear panel substrate are separated from each other, and after heating up to a temperature as high as possible, which is equal to or lower than the softening point of the glass for sealing to be used, it is preferable to stack and seal.

Therefore, for example, in the case of using a sealing glass having a softening point of about 400 ° C. which has been generally used in the past, in order to keep the sealing stable and reduce the influence of gas on the phosphor as much as possible. , The front panel substrate and the rear panel substrate are separated from each other, the temperature is raised to near 400 ° C., and then the front panel substrate and the rear panel substrate are superposed, and further heated to a softening point or higher for sealing. Considered good.

(2) If glass for sealing having a higher softening point is used, stable sealing can be achieved even if the front panel substrate and the rear panel substrate are heated to such a high temperature and heated. You will be able to Therefore, by using a glass for sealing having a high softening point as described above, the temperature is raised to near the softening point, and then the front panel substrate and the back panel substrate are superposed and further heated to a temperature equal to or higher than the softening point for sealing. By doing so, it is possible to further reduce the influence of the gas on the phosphor while keeping the sealing stable.

(3) On the other hand, in the front panel substrate or the back panel substrate, the front panel substrate and the back panel substrate are separated by devising such that the sealing glass layer formed on the outer periphery does not flow even if softened. Stable sealing can be achieved even when heated to a high temperature above the softening point of the glass for sealing in this state. For example, in the outer peripheral portion of the front panel substrate or the rear panel substrate, if a partition wall for preventing flow is formed between the region to which the sealing glass is applied and the display region, the display region when the sealing glass softens. Can be prevented from flowing out.

Therefore, after taking measures to prevent the sealing glass from flowing out, the front panel and the rear panel substrate are separated from each other and heated to a temperature higher than the softening point of the sealing glass to raise the temperature of the front panel. If the substrate and the back panel substrate are overlapped and sealed, the effect of gas on the phosphor can be further reduced while maintaining stable sealing. That is, in this case, since the front panel substrate and the rear panel substrate can be sealed without heating and heating after they are superposed, gas emission from the panels after superposition can be almost completely suppressed. Therefore, the sealing can be performed in a state where the phosphor is hardly subjected to thermal deterioration.

(Study on Atmosphere Gas and Pressure) As atmosphere gas to be circulated in the heating furnace 81 at the time of sealing,
It is desirable to use a gas containing oxygen, such as air, rather than a gas containing no oxygen. This is because, as described in the first embodiment, the oxide-based phosphor often used in the PDP tends to have lower luminous efficiency when heated in an oxygen-free atmosphere.

Although a certain effect can be obtained even if the outside air is sent as the atmospheric gas at the normal pressure, in order to enhance the effect of preventing the deterioration of the phosphor layer, dry gas such as dry air is fed into the heating furnace 81. It is desirable that the heating is performed while circulating or evacuation of the heating furnace 81. The reason why the dry gas is allowed to flow is that steam contained in the atmospheric gas does not cause thermal deterioration of the phosphor layer. Further, it is desirable to evacuate the inside of the heating furnace 81 in order to efficiently discharge the gas (water vapor etc.) released from the panel substrates 10 and 20 due to the heating.

When a dry gas is passed as the atmospheric gas, the lower the partial pressure of water vapor, the more the thermal deterioration of the blue phosphor layer is suppressed (see the experimental results of FIGS. 5 and 6 described in the first embodiment). In order to obtain a sufficient effect, the water vapor partial pressure is 15
It is desirable to set below Torr, and further, 10To
The lower the setting is rr, 5 Torr, 1 Torr, and 0.1 Torr, the more the effect can be expected.

(About application of glass for sealing) At the time of sealing the PDP, the glass for sealing is applied only to one substrate (generally only the back substrate side), and both substrates are superposed and sealed. It is common to do. By the way, in the present embodiment, since the rear panel substrate 20 is pressed against the front panel substrate 10 by the pressing mechanism 86 in the sealing device 80, it is difficult to press with a strong pressure so as to tighten with a clamp.

Therefore, if a sealing glass layer is formed and sealed only on the rear glass substrate side and the wettability between the sealing glass and the front glass plate is poor, the sealing by the sealing glass cannot be completed. However, if a sealing glass layer is formed on both the front glass substrate and the rear glass substrate, the front glass substrate and the rear glass substrate are completely adhered after sealing, so that the PDP can be manufactured with good yield. be able to.

The method of forming and sealing the sealing glass layer on both the front glass substrate and the rear glass substrate in this way is not limited to the case of the present embodiment, and is generally used for PDP manufacturing. In the process, it is effective for sealing with good yield. (Modification of this Embodiment) In the sealing device 80, the front panel substrate 10 and the rear panel substrate 2 are heated before heating.
After aligning and aligning 0 and 0, the rear panel substrate 20 is separated from the front panel substrate 10 by pushing up the rear panel substrate 20 with the moving pin 85, but the rear panel substrate 20 is separated from the front panel substrate 10. The method is not limited to this.

For example, in the example shown in FIG. 23, a frame 87 that fits outside the outer periphery of the front panel substrate 10 is suspended from above the heating furnace by a suspension rod 88 that slides up and down. The protruding portion of the back panel substrate 20 is placed on the frame 87 so that the back panel substrate 20 can be moved up and down in parallel. That is, by pulling up the frame 87 upward, the rear panel substrate 20 is separated from the front panel substrate 10, and by lowering the frame 87 downward, the rear panel substrate 20 is moved to the front panel substrate 1.
Can be overlaid on zero.

In the sealing device 80, the pressing mechanism 8
Although the rear panel substrate 20 is pressed against the front panel substrate 10 at 6, in the example shown in FIG. 23, a weight 89 is placed on the rear panel substrate 20 instead of providing the pressing mechanism 86. In this case, the rear panel substrate 20 is pressed against the front panel substrate 10 by the gravity applied to the weight 89 when the frame body 87 is lowered.

FIG. 24 is a diagram showing the operation of the sealing step in another modification. In the example of FIG. 24, in the sealing step, the rear panel substrate 20 is rotated in a state where the rear panel substrate 20 is partially brought close to the front panel substrate 10 so that the rear panel substrate 20 can be separated from the front panel substrate 10 or overlapped with each other. That is, in the upper part of the mounting table 84, as in the case of FIG. 20, a total of four pins 85a.
85b is provided, but a pair of pins 85a on one side (the left side in FIG. 24) support a fixed position of the rear panel substrate 20 at their tips (for example, the tip portion of the pins 85a is The rear panel substrate 20 is formed in a spherical shape.
Also, a spherical recess should be formed and fitted. ),
A pair of pins 85b on the other side (right side in FIG. 24) can be driven up and down.

In this case, as shown in FIG. 24 (a), the front panel substrate 10 and the rear panel substrate 20 are placed on the mounting table 84 in a state of being superposed, and as shown in FIG. By moving the pins 85b of the rear panel upward, the rear panel substrate 20 is centered around the tips of the pair of pins 85a.
Can be rotated and separated from the front panel substrate 10. In addition, as shown in FIG.
By moving 5b downward, the rear panel substrate 20
Can also be rotated in the opposite direction along the same path to be superposed in a state of being aligned with the front panel substrate 10.

In the state of FIG. 24B, the front panel substrate 10 and the rear panel substrate 2 are on the side of the pair of pins 85a.
Although it is in contact with 0, since the facing surface of the rear panel substrate 20 on which the phosphor layer is disposed is open, even if gas is generated, it is not confined in the internal space. (Example 5)

[0176]

[Table 5]

Panel No. Based on the present embodiment, the PDPs 41 to 50 perform the sealing process by changing the atmospheric gas and pressure when heating the front panel substrate and the back panel substrate, and the temperature and timing when they are superposed,
It is a produced example. The calcination was performed at 350 ° C. in each case. As the atmosphere gas, the panel No. 41-46,
At 48, 49 and 50, the water vapor partial pressure is 0 to 12 Torr.
Dry air set to various values within the range was used.
In addition, the panel No. In 47, heating was performed while evacuation was performed.

Panel No. In Nos. 43 to 47, the panel substrate was heated from room temperature to 400 ° C. in the sealing step.
When the temperature (lower than the softening point of the glass for sealing) was reached, both panel substrates were superposed. Then, when the temperature is further raised by heating to reach a sealing temperature of 450 ° C (a temperature above the softening point of the glass for sealing), the temperature is held for 10 minutes or longer, and then the exhaust temperature is lowered to 350 ° C and maintained at this exhaust temperature. While performing the exhaust process.

On the other hand, the panel No. 41 and 42, a slightly lower temperature of 250 ° C., 35
Both panel substrates were superposed at 0 ° C. Also, panel N
o. In No. 48, in the sealing step, after raising the sealing temperature to 450 ° C., both panel substrates are superposed and the panel N
o. In No. 49, both panel substrates were superposed after the sealing temperature (peak temperature) was raised to 500 ° C. in the sealing step.

Also, the panel No. In No. 50, in the sealing step, after the temperature was raised to the peak temperature of 480 ° C., the temperature was lowered to the sealing temperature of 450 ° C., and then both panel substrates were superposed and sealed. Panel No. In the PDP 51, based on the modification of the fifth embodiment shown in FIG. 24, both panel substrates are superposed and sealed after the sealing temperature (peak temperature) is raised to 450 ° C.

Panel No. The PDP No. 52 is a comparative example prepared by first stacking the front panel substrate and the rear panel substrate at room temperature, heating them to 450 ° C. in dry air at atmospheric pressure, and sealing them. The above panel No. In the PDPs Nos. 41 to 52, the phosphor film thickness is 30 μm, and the discharge gas is Ne (95%)-Xe (5
%), And the filling pressure was 500 Torr so that the panel configurations were the same.

<Light Emission Property Test> Test method and result: the above panel No. Each P of 41-52
Regarding DP, as the emission characteristics, the emission intensity and the chromaticity coordinate y when only the blue cell is turned on, the peak wavelength of the emission spectrum, and the panel brightness and color temperature in white balance without color correction, the blue cell and the green cell The peak intensity ratio of the emission spectrum when light was emitted at the same power was measured.

Further, each produced PDP was disassembled, and the blue phosphor layer of the rear panel substrate was irradiated with vacuum ultraviolet rays (center wavelength 146 nm) using a krypton excimer lamp, and the chromaticity coordinate y of the emitted light was measured. The results of these measurements are as shown in Table 5. The emission intensity of the blue cell shown in Table 5 is as shown in Panel No. The emission intensity of 52 (Comparative Example) was 10
The relative emission intensity is set to 0.

Further, each produced PDP was disassembled, and the rear panel substrate was irradiated with vacuum ultraviolet rays by using a krypton excimer lamp, and the color temperature at the time of emitting all colors and the emission spectrum when emitting blue and green light were obtained. When the peak intensity ratio was measured, the same result as that obtained by the above lighting was obtained. Further, FIG. 45, 50, 52
FIG. 3 is an emission spectrum of the PDP when only the blue cell is turned on.

Although not shown in Table 5, the chromaticity coordinates x and y of the emission colors of the red cell and the green cell are shown in the panel No. All of 41 to 53 have substantially the same value, red is (0.636, 0.350) and green is (0.251,
It was 0.692). In the PDP of the comparative example, the chromaticity coordinate of the blue cell emission color was (0.170, 0.090), and the peak wavelength of the emission spectrum was 458 nm.

Further, take out the blue phosphor from the panel,
The number of H ₂ O gas molecules desorbed from 1 g of the blue phosphor at 200 ° C. or higher was measured by the TDS analysis method. The ratio of the c-axis length to the a-axis length of the blue phosphor crystal was also measured by X-ray diffraction. Table 5 also shows these results. Consideration: Panel No. 41-51 and panel No. 52 and panel No. 52, the panel No. 41-5
Panel No. 1 in each case 52, the light emission characteristics are superior (the relative light emission intensity is high and the chromaticity coordinate y is small). It is considered that this is because the sealing method according to the above-described embodiment reduces the amount of gas released into the internal space after the two panel substrates are superposed on each other, as compared with the sealing method according to the comparative example.

Panel No. In the PDP of No. 52, the chromaticity coordinate y of blue emission is 0.088, and in this case, the color temperature in the white balance without color correction is 5800K, while the panel No. In Nos. 41 to 51, the chromaticity coordinate y of blue light emission is 0.08 or less, and the color temperature in the white balance without color correction is 6500K or more. In particular, the panel No. Four
In a PDP having a low chromaticity coordinate y of blue, such as 8, 49, 50, and 51, a high color temperature of about 11000K is realized with white balance without color correction.

FIG. 26 is a diagram showing the CIE chromaticity diagram of the color reproduction region near blue for the PDPs of the example and the comparative example. In the area (a) in the figure, the chromaticity coordinate y of blue emission is 0.09 (the peak wavelength of the emission spectrum is 458 nm).
As for the case (corresponding to panel No. 52), the region (b) has a chromaticity coordinate y of blue emission of about 0.08 (peak wavelength of emission spectrum is 455 nm) (panel N).
o. 41), the region (c) has a chromaticity coordinate y of blue emission of 0.052 (the peak wavelength of the emission spectrum is 4).
48 nm) (corresponding to panel No. 50), the color reproduction range near blue is shown.

From this figure, the color reproduction range near blue is
It can be seen that, as compared with (a), it becomes wider in (b) and further wider in (c). This indicates that as the chromaticity coordinate y of blue cell emission becomes smaller (the peak wavelength of the emission spectrum becomes shorter), a PDP having a wider color reproduction range near blue can be realized. Next, panel No. Comparing the emission characteristics among 41, 42, 45, and 48 (the water vapor partial pressure of dry air is 2 Torr),
Panel No. The emission characteristics are improved in the order of 41, 42, 45, 48 (the relative emission intensity is high and the chromaticity coordinate y is small). From this result, it is understood that the higher the temperature at which the front panel substrate 10 and the rear panel substrate 20 are superposed on each other, the higher the emission characteristics of the PDP.

This is because as the front panel substrate 10 and the rear panel substrate 20 are separated from each other, they are preheated to a higher temperature.
It is considered that the gas released from each panel substrate can be sufficiently exhausted, so that the amount of gas released into the internal space after the both panel substrates are superposed is reduced. In addition, the panel No. Panel No. 43, 44, 45, and 46 (having the same temperature profile in the sealing step) were compared in terms of light emission characteristics. The emission characteristics are improved in the order of 43, 44, 45, 46 (the chromaticity coordinate y is small). From this result, it is understood that the light emission characteristics are improved as the water vapor partial pressure in the atmosphere gas is lower.

Further, the panel No. 46 and panel no.
Comparing the emission characteristics of No. 47 (having the same temperature profile in the sealing step), panel No. 46 is PDP
The light emission characteristics of are slightly better. This is the panel No. Four
In No. 6, panel No. 6 was preheated in an atmosphere gas containing oxygen, whereas in Panel No. In No. 47, since it was preheated in an oxygen-free atmosphere, it is considered that oxygen in the phosphor, which is an oxide, was partly removed and an oxygen defect was formed.

Further, the panel No. 48 and panel no.
Comparing the emission characteristics of No. 51, it can be seen that the emission characteristics are almost the same. This is when preheating
It is shown that there is almost no difference in the emission characteristics of the PDP between the case where the facing surfaces of the front panel substrate 10 and the rear panel substrate 20 are completely separated and opened, and the case where they are opened in a state of being partially in contact with each other. .

In addition, each panel No. shown in Table 5 In, the chromaticity coordinate y of the light emitted when the blue phosphor layer is excited by vacuum ultraviolet rays and the chromaticity coordinate y when only the blue cell is turned on show substantially the same value. Moreover, each panel No. shown in Table 5 was used. Looking at the relationship between the chromaticity coordinate y of blue light emission and the peak wavelength of blue light emission in, the smaller the value of the chromaticity coordinate y of blue light emission, the shorter the peak wavelength of blue light emission. This indicates that the chromaticity coordinate y value of blue light emission is small and that the peak wavelength of blue light emission is short. [Sixth Embodiment] The PDP of the present embodiment has the same configuration as the PDP of the first embodiment shown in FIG.

The manufacturing method of the PDP is almost the same as that of the fifth embodiment, except that at least one of the front panel substrate 10 and the rear panel substrate 20 is coated with the sealing glass, and then the sealing device 80 is heated. The difference is that the calcination process, the sealing process, and the exhaust process are continuously performed in the furnace 81. Hereinafter, the calcination / sealing / exhaust steps in the present embodiment will be described in detail below.

The calcination step / sealing step / evacuating step of this embodiment is performed using the sealing apparatus shown in FIGS. However, in the present embodiment, as shown in FIG. 27, a pipe 90 inserted from the outside of the heating furnace 81 is connected to the glass tube 26 attached to the ventilation hole 21 a of the rear panel substrate 20. FIG. 27 is a diagram showing an operation when a calcination process to an exhaust process are performed using this sealing device.

The calcination / preheating / sealing / exhausting steps will be described with reference to this figure. Calcining step: In advance, the outer peripheral portion of the facing surface of the front panel substrate 10 (the surface facing the rear panel substrate 20) or the outer peripheral portion of the facing surface of the rear panel substrate 20 (the surface facing the front panel substrate 10), or The sealing glass layer 15 is formed by applying a sealing glass paste to the outer peripheral portions of the facing surfaces of both the front panel substrate 10 and the rear panel substrate 20 (note that in the figure, the sealing glass layer 15 is the front face). It is formed on the opposite surface of the panel substrate 10.).

Then, with the front panel substrate 10 and the rear panel substrate 20 aligned and superposed, they are placed in a fixed position on the mounting table 84, and the pressing mechanism 86 is set to press the rear panel substrate 20. (See FIG. 27 (a)). Next, the following operation is performed while circulating the atmospheric gas (dry air) in the heating furnace 81 (or while using vacuum exhaust from the gas exhaust valve 83).

The moving pin 85 is raised to push the rear panel substrate 20 upward to move it in parallel (FIG. 27B).
reference). As a result, the gap between the facing surfaces of the front panel substrate 10 and the rear panel substrate 20 is widened, and the rear panel substrate 2
The surface on which the 0 phosphor layer 25 is arranged is opened to a large space in the heating furnace 81. In this state, the inside of the heating furnace 81 is heated to the calcination temperature (about 350 ° C.) and heated, and the calcination temperature is maintained for about 10 to 30 minutes to perform calcination.

Preheating step: The panel substrates 10 and 20 are further heated and heated to release the gas adsorbed on the panel substrates 10 and 20. Then, at a predetermined temperature (for example, 40
(0 ° C.), the preheating step is finished. Sealing step: Subsequently, the moving pin 85 is lowered and the rear panel substrate 20 is overlaid on the front panel substrate 10 again. At this time, the rear panel substrate 20 is overlaid in the original aligned state (see FIG. 27C).

When the temperature in the heating furnace 81 reaches the sealing temperature (about 450 ° C.) higher than the softening point of the sealing glass layer 15, the sealing temperature is maintained for 10 to 20 minutes. At this time, the outer peripheral portions of the front panel substrate 10 and the rear panel substrate 20 are sealed by the softened sealing glass. During this time, since the rear panel substrate 20 is pressed against the front panel substrate 10 by the pressing mechanism 86, stable sealing can be performed.

Exhaust process: The inside of the heating furnace 81 is lowered to an exhaust temperature lower than the softening point of the glass for sealing, and the two panels are sealed while being baked at the exhaust temperature (for example, about 350 ° C. for 1 hour). High vacuum (8 × 10 ^-7 T
The inner space is degassed by evacuating to orr). This evacuation process is performed by connecting a vacuum pump (not shown) to the pipe 90.

After this evacuation process, the panel substrate is cooled to room temperature while keeping the internal space in vacuum, the discharge gas is sealed from the glass tube 26 into the internal space, and the ventilation port 21a is sealed to close the glass tube. A PDP is made by cutting 26. (Regarding the effect of the sealing method of the present embodiment) Conventionally, the calcination step, the sealing step, and the exhaust step were separately performed using a heating furnace, and the substrate was cooled to room temperature in the step and the step, It takes a long time to heat and raise the temperature in a later step and consumes a large amount of energy, but in the present embodiment, the calcination step, the preheating step, the sealing step, and the exhaust step must be cooled to room temperature. However, since the steps are continuously performed in the same sealing device, these series of steps can be performed quickly and the energy consumption for heating can be reduced.

Further, in the present embodiment, the calcination step and the preheating step are performed while the temperature inside the heating furnace 81 is being raised to the sealing temperature at which the sealing step is performed. Can be performed more quickly and with lower energy consumption. Furthermore, after the sealing process, the exhaust process is performed while the temperature of the sealed substrate is being lowered to room temperature, so from the sealing process to the exhaust process. Can be performed more quickly and with lower energy consumption.

Furthermore, according to the sealing method of the present embodiment, as compared with the conventional sealing method, as described below, the same effects as those of the above-mentioned fifth embodiment are exhibited. Usually, gases such as water vapor are adsorbed on the front panel substrate and the rear panel substrate, but when these substrates are heated and heated, the adsorbed gas is released. In the conventional general manufacturing method,
After the calcination step, in the sealing step, the front panel substrate and the rear panel substrate are superposed at room temperature and then heated and heated for sealing, so during the sealing step, the front panel substrate and the rear panel substrate are The adsorbed gas is released. Even if the gas adsorbed on the substrate is released to some extent in the calcination step, the gas is adsorbed again by bringing the temperature to room temperature in the atmosphere until the start of the sealing step. Occurs. Here, since the released gas is confined in the narrow internal space, the phosphor layer is thermally deteriorated due to the influence of the water vapor released from the protective layer 14, and the emission intensity thereof is likely to decrease.

On the other hand, according to the manufacturing method of this embodiment, the gas such as water vapor adsorbed on the front panel substrate 10 and the rear panel substrate 20 is released by the sealing step and the preheating step. At this time, both panel substrates 10
Since the wide gap is formed between the 20, the generated gas is not confined in the internal space. After the preheating, both panel substrates 10 and 20 are sealed in a heated state. Therefore, after the preheating, both panel substrates 10 and 20 are sealed.
No water will be adsorbed on. Therefore, the gas generated from both panel substrates 10 and 20 at the time of sealing is reduced,
The thermal deterioration of the phosphor layer 25 is prevented.

Further, by using the sealing device 80 as described above, if the front panel substrate 10 and the rear panel substrate 20 are first aligned with each other, sealing is performed in the aligned state. Further, in the present embodiment, since the preheating step to the sealing step are performed in the atmosphere in which the dry air flows, the phosphor layer 25 is not thermally deteriorated by the water vapor in the atmospheric gas.

Regarding the temperature to be raised by the preheating, the preferable condition of the timing of stacking the front panel substrate and the rear panel substrate, and the preferable conditions of the kind of atmospheric gas, the pressure, and the partial pressure of water vapor, the above-mentioned embodiment is performed. Form 5
It is as explained in. (Modification of the present embodiment) In the present embodiment, as described above, the calcination step-preheating step-sealing step-exhaust step was continuously performed in the same apparatus, but preheating The steps can be omitted, and even in that case, the same effect can be obtained to some extent. Further, even if only the calcination step-sealing step is continuously performed in the same apparatus, or only the sealing step-exhaust step is continuously performed in the same apparatus, some effects cannot be obtained. it can.

Further, in the present embodiment, after the sealing step, the inside of the heating furnace 81 is lowered to the exhaust temperature (350 ° C.) lower than the softening point of the glass for sealing, and then the exhaust step is performed. If the exhaust process is performed at a temperature as high as the sealing temperature, it is possible to exhaust sufficiently in a short time. However, in this case, it is considered necessary to take measures for preventing the glass for sealing from flowing out (for example, the flow stop partition wall shown in FIGS. 10 to 16).

In addition, in this embodiment, at the time of sealing,
The calcination step and the preheating step were performed with the facing surfaces of the front panel substrate 10 and the rear panel substrate 20 open, but the front panel substrate 10 and the rear panel substrate 20 were positioned as in the third embodiment. Even in the case where the inner space is depressurized and the inner space is heated and the temperature is raised while the dry air is being heated to perform the sealing, the calcining step-sealing step-exhaust step is performed by the same apparatus as described below. It is possible to carry out continuously in the.

That is, using the sealing heating device 50 of FIG.
At least one of the front panel substrate 10 and the rear panel substrate 20 is provided with a sealing glass to form a sealing glass layer 15 on the opposing surface thereof, and the sealing glass layer 15 is superposed while being aligned without calcination. insert. Then, the glass tube 26a attached to the vent hole 21a of the rear panel substrate 20.
The pipe 52a is connected to the pipe 52a, and the pipe 52a is evacuated by a vacuum pump (not shown). At the same time, the pipe 52b is attached to the glass tube 26b attached to the vent hole 21b of the rear panel substrate 20.
Are connected to each other and the dry air is fed thereinto, so that the inner space between the panel substrates 10 and 20 is brought into a state in which the dry air flows while the pressure is reduced.

Then, while maintaining the internal space between both panel substrates 10 and 20 in this state, the inside of the heating furnace 51 is heated to the calcination temperature and calcined (350 ° C., hold for 10 to 30 minutes). . At this time, the calcination cannot be sufficiently performed because oxygen is difficult to be supplied to the sealing glass layer only by heating and heating the panels in a state where the front panel substrate 10 and the rear panel substrate are superposed on each other, but as described above. If calcination is performed while flowing dry air inside the panel, calcination can be sufficiently performed.

Next, further sealing is carried out by heating up to a sealing temperature above the softening point of the sealing glass and holding it (for example, the peak temperature is held at 450 ° C. for 30 minutes). Then, the inside of the heating furnace 51 is lowered to an exhaust temperature lower than the softening point of the glass for sealing, and while maintaining the exhaust temperature, high-vacuum exhaust is performed from the internal spaces of the both panel substrates that are sealed, thereby After degassing and exhausting process,
The panel substrate is cooled to room temperature, the discharge gas is sealed from the glass tube 26 into the internal space, the vent hole 21a is sealed, and the glass tube 26 is cut out to manufacture a PDP.

Also in the case of this modification, similarly to the present embodiment, the calcination step, the sealing step, and the exhaust step are continuously performed in the same sealing apparatus without lowering the temperature to room temperature. Therefore, the series of steps can be performed quickly and the energy consumption for heating can be reduced. In this modification, in the heating furnace 51, only the calcination step-sealing step,
Alternatively, it is possible to continuously perform only the sealing process and the exhaust process. (Example 6)

[0214]

[Table 6]

Panel No. Reference numerals 61 to 69 denote PDPs according to the examples produced based on the present embodiment, which are sealed by changing the atmosphere gas and pressure when heating the front panel substrate and the rear panel substrate, and the temperature and timing when they are superposed. The dressing process was performed. 28 shows the panel No.
It is the temperature profile used in the calcination step-sealing step-exhaust step when manufacturing PDPs 63 to 67.

As the atmosphere gas, the panel No. 61-6
In Panel Nos. 6, 68, and 69, the dry air in which the partial pressure of water vapor was set to various values within the range of 0 to 12 Torr was used. In 70, undried air was used. In addition, the panel No. In 67, heating was performed while evacuation was performed. Panel No. In 63 to 67, the panel substrate was heated from room temperature to 350 ° C., and when it reached 350 ° C., it was held at 350 ° C. for 10 minutes for calcination, and further heated to 400 ° C. (from the softening point of the sealing glass. When the temperature reached low, both panel substrates were overlaid. Then, when the temperature is further increased by heating to reach a sealing temperature of 450 ° C (a temperature above the softening point of the glass for sealing), the temperature is maintained for 10 minutes or more, and then the temperature inside the furnace is lowered to 350 ° C and maintained at 350 ° C. While performing the exhaust process.

On the other hand, the panel No. In the sealing process of 61 and 62, a slightly lower temperature of 250 ° C and 350 ° C
Then, both panel substrates were overlapped. In addition, the panel No.
In the sealing step of No. 68, after raising the sealing temperature to 450 ° C., both panel substrates are superposed and the panel No. In the sealing step of No. 69, after the temperature was raised to the peak temperature of 480 ° C. and then the temperature was lowered to the sealing temperature of 450 ° C., both panel substrates were superposed and sealed.

Panel No. 70 is a PDP according to a comparative example
However, as in the conventional sealing process, after calcination, the front panel substrate and the back panel substrate are superposed at room temperature and heated to a sealing temperature of 450 ° C. in air at atmospheric pressure for sealing. The temperature was once lowered to room temperature. Then, the exhaust gas was heated again to 350 ° C. in the heating furnace, and the exhaust process was performed while maintaining the exhaust temperature at 350 ° C.

The above panel No. 61 to 70, the thickness of the phosphor layer was 30 μm, and the discharge gas was Ne (95
%)-Xe (5%), and the filling pressure was 500 Torr so that the panel configurations would be the same. <Luminescence characteristic test> Test method and result: the above panel No. 61-70 of each P
Regarding DP, as the emission characteristics, the emission intensity and the chromaticity coordinate y when only the blue cell is turned on, the peak wavelength of the emission spectrum, the color temperature in white balance without color correction, the blue cell and the green cell have the same power. The peak intensity ratio of the emission spectrum when light was emitted at was measured.

The results of these measurements are shown in Table 6. The emission intensity of the blue cell shown in Table 6 is as shown in panel N
o. It is a relative emission intensity with the emission intensity of 70 as 100. Further, each PDP produced is disassembled, and the rear panel substrate is irradiated with vacuum ultraviolet rays by using a krypton excimer lamp to emit chromaticity coordinates y of blue light emission, color temperature at all color light emission, and blue and green light. When the peak intensity ratio of the emission spectrum at that time was measured, the same result as that obtained by the above lighting was obtained.

Further, take out the blue phosphor from the panel,
The number of H ₂ O gas molecules desorbed from 1 g of the blue phosphor at 200 ° C. or higher was measured by the TDS analysis method. The ratio of the c-axis length to the a-axis length of the blue phosphor crystal was also measured by X-ray diffraction. Table 6 also shows these results. Consideration: Panel No. 61 to 69 and panel No. Comparing the light emission characteristics of panel No. 70 and panel No. 70, 61-6
In any of No. 9, panel No. 70 is superior in light emission characteristics (high relative light emission intensity and small chromaticity coordinate y). This is the panel No. According to the sealing method used in Nos. 61 to 69, panel No. It is considered that the amount of gas released to the internal space after the both panel substrates are superposed is smaller than that in the sealing method used in 70.

Panel No. In the PDP of 70, the chromaticity coordinate y of blue light emission is 0.090, and the color temperature in the white balance without color temperature correction is 5800K.
Panel No. In Nos. 61 to 69, the chromaticity coordinate y of blue light emission is 0.08 or less, and the color temperature in the white balance without color temperature correction is 6500K or more. In particular, the panel No. 68,
In a PDP having a low chromaticity coordinate y of blue like 69, a high color temperature of about 11000K is realized with white balance without color correction.

Next, the panel No. 61, 62, 65, 6
8,69 (both dry air has a water vapor partial pressure of 2 Torr)
Comparing the light emission characteristics between panel No. r) and panel No. r. 61,
The emission characteristics are improved in the order of 62, 65, 68, 69 (the relative emission intensity is high and the chromaticity coordinate y is small). From this result, it is understood that the higher the temperature at which the front panel substrate 10 and the rear panel substrate 20 are superposed is set, the more the light emission characteristics are improved.

Further, the panel No. 63, 64, 65, 6
Comparing the light emission characteristics between No. 6 (having the same temperature profile in the sealing step), the panel No. 63, 64, 65, 6
In the order of 6, the emission characteristics are improved (the chromaticity coordinate y is small). From this result, it is understood that the light emission characteristics are improved as the water vapor partial pressure in the atmosphere gas is lower. Also, panel N
o. 66 and panel no. 67 (when the temperature profile in the sealing step is the same), the emission characteristics are compared. 66 has a slightly better light emission characteristic.

This is the panel number. In No. 66, the panel No. 66 is heated in the atmosphere gas containing oxygen. It is considered that the sample No. 67 is heated in an oxygen-free atmosphere, and when the phosphor layer is heated in the oxygen-free atmosphere, oxygen in the phosphor that is an oxide partly escapes to form an oxygen defect. (Other matters) In the first to sixth embodiments described above,
The case of manufacturing a surface discharge type PDP has been described.
The present invention can be applied to the case of manufacturing a counter discharge type PDP.

Further, as the composition of the phosphor forming the phosphor layer, other than those shown above, those generally used for the phosphor layer of the PDP can be used in the same manner. You can Further, as shown in the first to sixth embodiments, it is general that the sealing glass is applied after the phosphor layer is formed, but it is conceivable that the order may be changed.

[0227]

As described above, according to the PDP manufacturing method of the present invention, the steps of heating the disposed phosphors (phosphor firing step, sealing material calcination step, sealing step, exhaust gas) Process) is performed in a dry gas atmosphere or in an atmosphere in which the dry gas flows under reduced pressure, so that the chromaticity coordinate y (CIE color system) or the blue phosphor of the emission color when only the blue cell is turned on. It is possible to manufacture a PDP with excellent emission chromaticity such that the chromaticity coordinate y of the light emitted when the layer is excited by vacuum ultraviolet rays is 0.08 or less.

With such a PDP, the color temperature in the white balance can be set to 7,000 K or more, and further 800
It is also possible to set it to 0K or more, 9000K or more, and 10000K or more. Further, if the emission chromaticity of the blue phosphor layer is improved, the color reproducibility is also improved. In addition, as described above, the PDP having excellent emission chromaticity of the blue phosphor layer is a method of calcining the front substrate and the rear substrate in a state where the facing surfaces are opened, and the front substrate and the rear substrate in a dry gas in the internal space. It is also possible to manufacture by using a method of sealing while flowing, or a method of preheating the front substrate and the rear substrate in a state where the facing surfaces are opened and then sealing the both substrates by overlapping. .

[0229] Further, after performing a sealing step of sealing the sealing material at the sealing temperature in a state where the front panel substrate and the rear panel substrate were superposed on each other, they were sealed without lowering to room temperature. After starting the exhausting step of exhausting the gas in the internal space between the two substrates, or after the sealing material calcination step of calcining the substrate provided with the sealing material at the calcination temperature, It can also be manufactured by starting the sealing process without lowering the temperature of the substrate to room temperature. In this case, the time required for heating and the energy consumption can be reduced.

[0230]

[Brief description of drawings]

FIG. 1 is a main part perspective view showing an AC surface discharge PDP according to a first embodiment.

FIG. 2 is a diagram showing a PDP display device in which a drive circuit is connected to the PDP.

FIG. 3 is a diagram showing a configuration of a belt-type heating device used in the first embodiment.

FIG. 4 is a diagram showing a configuration of a sealing heating device used in the first embodiment.

FIG. 5 is a result of relative emission intensity measurement when a blue phosphor is fired in air with a changed partial pressure of water vapor.

FIG. 6 is a measurement result of chromaticity coordinates y when a blue phosphor is fired in air with a changed water vapor partial pressure.

FIG. 7 is an example of a measurement result of measuring the number of H ₂ O molecules desorbed from the blue phosphor.

FIG. 8 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 9 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 10 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 11 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 12 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 13 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 14 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 15 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 16 is a diagram showing a specific example of a back glass substrate in the second embodiment.

FIG. 17 is a characteristic diagram showing water vapor partial pressure dependence of the effect of recovering the light emission characteristics by re-baking in blue after the blue phosphor is once thermally deteriorated.

FIG. 18 is a characteristic diagram showing water vapor partial pressure dependence of the effect of recovering the light emitting characteristics by re-baking the blue phosphor in the air after thermally degrading it.

FIG. 19 is a diagram showing a configuration of a sealing device used in a sealing step in the fifth embodiment.

FIG. 20 is a perspective view showing an internal configuration of a heating furnace in the sealing device.

FIG. 21 is a diagram showing an operation when performing a preheating step and a sealing step using the sealing device.

FIG. 22 is a diagram showing a result of time-dependent measurement of the amount of water vapor released from the MgO layer in the experiment according to the fifth embodiment.

FIG. 23 is a diagram showing a modified example of the sealing device according to the fifth exemplary embodiment.

FIG. 24 is a diagram showing an operation of another modification of the sealing device according to the fifth exemplary embodiment.

FIG. 25 is an emission spectrum of Example 5 PDP when only the blue cell is turned on.

FIG. 26 is a diagram showing a color reproduction region near blue for the PDPs of Example 5 and Comparative Example on a CIE chromaticity diagram.

FIG. 27 is a diagram showing an operation when performing a calcination process to an exhaust process using the sealing device in the sixth embodiment.

28 is a temperature profile used in a calcination step-sealing step-exhaust step when manufacturing a PDP in Example 6. FIG.

FIG. 29 is a schematic sectional view showing an example of a general alternating-current (AC) PDP.

[Explanation of symbols]

10 Front panel board 11 Front glass substrate 12a, 12b display electrodes 13 Dielectric layer 14 Protective layer 15 Sealed glass layer 20 Back panel board 21 Rear glass substrate 21a, 21b vent 22 Address electrode 23 Dielectric layer 24 partitions 25 Phosphor layer 26 glass tubes 30 discharge space 40 heating device 41 heating furnace 42 Conveyor belt 43 Gas introduction pipe 50 Heating device for sealing 51 heating furnace 53 gas supply source 54 vacuum pump 60 sealing glass area 70 Drain bulkhead 80 Sealing device

Continuation of the front page (31) Priority claim number Japanese Patent Application No. 10-222987 (32) Priority date August 6, 1998 (8.6.8.6) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 11-39280 (32) Priority date February 17, 1999 (Feb. 17, 1999) (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 11-137764 (32) Priority date May 18, 1999 (May 18, 1999) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 11-137763 (32) Priority Japan May 18, 1999 (May 18, 1999) (33) Priority claiming country Japan (JP) (72) Inventor Masaki Aoki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56 ) Reference JP-A-5-234512 (JP, A) JP-A-5-211031 (JP, A) JP-A-60-221926 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) H01J 9/227 H01J 9/26 H01J 9/38-9/395 H01J 11/00-17/49

Claims (29)

(57) [Claims] 1. A phosphor disposing step of disposing a phosphor containing at least a blue phosphor on at least one of facing surfaces of a front substrate and a back substrate, and a heating step of heating a substrate on which the phosphor is disposed. And the heating step is performed in the phosphor providing step.
The phosphor firing step for firing the phosphor while flowing a dry gas
A method of manufacturing a plasma display panel, which is a step . 2. A phosphor layer forming step of forming a phosphor layer containing at least a blue phosphor on at least one of the facing surfaces of the front substrate and the back substrate, and sealing on at least one of the facing surfaces of the front substrate and the back substrate. A sealing material layer forming step of forming a material layer, and stacking the front substrate and the rear substrate so that an internal space is formed between the substrates after the phosphor layer forming step and the sealing material layer forming step. And a sealing step in which the sealing material is sealed by maintaining the sealing temperature at a temperature equal to or higher than the temperature at which the sealing material softens, and the sealing step does not flow dry gas into the internal space.
And a plasma display panel manufacturing method. 3. A phosphor layer forming step of forming a phosphor layer containing at least a blue phosphor on at least one of the facing surfaces of the front substrate and the back substrate, and Mg on at least one of the facing surfaces of the front substrate and the back substrate.
An MgO layer forming step of forming an O layer, a sealing material layer forming step of forming a sealing material layer on at least one of the facing surfaces of the front substrate and the back substrate, the phosphor layer forming step, the MgO layer forming step, and After the step of forming the sealing material layer, the front substrate and the rear substrate are superposed such that an internal space is formed between the substrates, and the sealing temperature is maintained at a temperature higher than the softening temperature of the sealing material. A method of manufacturing a plasma display panel, comprising: a sealing step of sealing by means of :
A method for manufacturing a plasma display panel, which is performed while flowing a dry gas into the internal space . 4. The method of claim 2 or 3 wherein the sealing step is performed while alternately repeating an operation for discharging the gas from the operation and the interior space is filled with a dry gas into the interior space
A method for manufacturing a plasma display panel according to any one of 1 . Wherein said sealing step, according to claim 2 or 3, characterized in that made while flowing dry gas while maintaining the pressure in the inner space lower sealing pressure than the atmospheric pressure Of manufacturing plasma display panel of. Wherein said sealing pressure, plasma display panel manufacturing method of claim 5, wherein a is less than 500 Torr. Wherein said sealing pressure, plasma display panel manufacturing method of claim 5, wherein a is less than 300 Torr. 8. After heating heating the front and rear substrates in a state of exposing the phosphor layer to a pressure higher than the sealing pressure, and the gas pressure of the internal space is lowered to the sealing pressure The method for manufacturing a plasma display panel according to claim 5, wherein the sealing step is started. 9. The gas pressure in the internal space after heating the front substrate and the rear substrate to a temperature higher than the softening point of the sealing material while exposing the phosphor layer to a pressure higher than the sealing pressure. 9. The method for manufacturing a plasma display panel according to claim 8, wherein the sealing step is started by lowering the sealing pressure to the sealing pressure. 10. the front and rear substrates in a state of exposure of the phosphor layer to a pressure higher than the sealing pressure, 300 ° C.
9. The method of manufacturing a plasma display panel according to claim 8 , wherein after the heating and heating, the gas pressure in the internal space is reduced to the sealing pressure to start the sealing step. 11. The front substrate and the rear substrate are heated to 350 ° C. while the phosphor layer is exposed to a pressure higher than the sealing pressure.
9. The method of manufacturing a plasma display panel according to claim 8 , wherein after the heating and heating, the gas pressure in the internal space is reduced to the sealing pressure to start the sealing step. 12. the front and rear substrates in a state of exposure of the phosphor layer to a pressure higher than the sealing pressure, 400 ° C.
9. The method of manufacturing a plasma display panel according to claim 8 , wherein after the heating and heating, the gas pressure in the internal space is reduced to the sealing pressure to start the sealing step. 13. The method of manufacturing a plasma display panel according to claim 8 , wherein in the sealing step, gas is forcibly exhausted from the internal space. 14. In the sealing step, a plurality of barrier ribs arranged in stripes are interposed inside the sealing material layer between the front substrate and the rear substrate, and each of the plurality of barrier ribs is disposed. There is a pair of first gaps between the longitudinal ends and the sealing material layer, and the minimum width of the first gaps is that the ones are arranged at the outermost side among the plurality of partition walls. a larger state than the minimum width of the second gap that exists between the sealing material layer, the dry gas, according to claim 2, characterized in that the flow to the other from one of the pair of first gap Or any of 3
A method for manufacturing a plasma display panel as described in 1. 15. In the sealing step, a plurality of first barrier ribs arranged in stripes inside the sealing material layer between the front substrate and the back substrate, and inside the sealing material layer. A second partition provided along the
In addition, a first gap exists between each longitudinal end of the plurality of first partition walls and the second partition wall, and a minimum width of the first gap is the largest among the plurality of first partition walls. The dry gas is in a state of being larger than the minimum width of the second gap existing between the second partition and the one arranged outside, and the dry gas is circulated from one of the pair of first gaps to the other. Either of claim 2 or 3 characterized by
A method for manufacturing a plasma display panel as described in 1. 16. A phosphor layer forming step of forming a phosphor layer on at least one of the facing surfaces of the front substrate and the back substrate, and providing a sealing material on at least one of the facing surfaces of the front substrate and the back substrate. After the sealing material disposing step, the phosphor layer forming step and the sealing material disposing step, the front substrate and the rear substrate are superposed so that an internal space is formed between the substrates, A sealing step in which the sealing material is sealed by maintaining the sealing temperature at a temperature higher than the softening temperature of the sealing material; In the method for manufacturing a plasma display panel, the sealing step comprises applying a dry gas to the internal space.
A method of manufacturing a plasma display panel, wherein the exhausting step is performed without lowering the temperatures of both substrates sealed in the sealing step to room temperature. 17. A phosphor layer forming step of forming a phosphor layer on at least one of the facing surfaces of the front substrate and the back substrate; and providing a sealing material on at least one of the facing surfaces of the front substrate and the back substrate. Sealing material disposing step, sealing material calcining step of calcining the substrate on which the sealing material is disposed by calcining at a calcining temperature, phosphor layer forming step and sealing material calcining step After that, the front substrate and the rear substrate are overlapped with each other so that an internal space is formed between the two substrates, and are sealed by maintaining the sealing temperature at a temperature higher than the temperature at which the sealing material is softened. In the method of manufacturing a plasma display panel, the sealing step comprises applying a dry gas to the inner space.
The sealing material calcination step is performed by the front substrate and the rear substrate.
Are stacked so that an internal space is formed between the two substrates.
In the plasma display panel, the sealing step is started without causing the substrate heated in the sealing material calcination step to cool down to room temperature. Production method. 18. A phosphor layer forming step of forming a phosphor layer on at least one of the facing surfaces of the front substrate and the back substrate, and disposing a sealing material on at least one of the facing surfaces of the front substrate and the back substrate. Sealing material disposing step, sealing material calcining step of calcining the substrate on which the sealing material is disposed by calcining at a calcining temperature, phosphor layer forming step and sealing material calcining step After that, the front substrate and the rear substrate are overlapped with each other so that an internal space is formed between the two substrates, and are sealed by maintaining the sealing temperature at a temperature higher than the temperature at which the sealing material is softened. and wear steps, in the manufacturing method of a plasma display panel having an exhaust step for exhausting the gas in the inner space between the substrates while keeping the substrates that are sealed to high exhaust temperatures than room temperature, the sealing step, the internal While flowing dry gas into the space
The calcination step is performed on both the front substrate and the rear substrate.
Stacked so that an internal space is formed between the substrates
In a state in which the front substrate and the rear substrate are kept at a temperature higher than room temperature from the sealing material calcination step to the sealing step to the exhaust step. A method of manufacturing a plasma display panel, comprising: 19. After the calcination step, according to claim 17 in which the substrate is heated to a calcining temperature was further Atsushi Nobori to sealing temperature, characterized in that to start the sealing step
19. The method for manufacturing a plasma display panel according to any one of 18 . 20. The plasma according to claim 16, wherein after the sealing step, the temperature of both the sealed substrates is lowered to the exhaust temperature before the exhaust step is started. Display panel manufacturing method. 21. After the sealing step, according to claim 16 or the temperature of the substrates ^ which is sealed, characterized in that to start the pumping step while maintaining the sealing temperature and the same temperature
19. The method for manufacturing a plasma display panel according to any one of 18 . 22. The calcination step is performed in a state where the facing surface of the substrate on which the sealing material is arranged is open, and in a dry gas atmosphere between the calcination step and the sealing step. , The front substrate and the back substrate,
The method of manufacturing a plasma display panel according to any one of claims 17 to 18, further comprising a preheating step of heating with the facing surface open. 23. The method of manufacturing a plasma display panel according to claim 22 , wherein in the preheating step, the front substrate and the rear substrate are heated to a temperature higher than a calcination temperature. 24. In the preheating step, the front substrate and the rear substrate are heated to a temperature higher than a sealing temperature, and then the front substrate and the rear substrate are cooled to a sealing temperature and then sealed. The step of starting a step.
22. A method for manufacturing a plasma display panel according to item 22 . 25. The method of manufacturing a plasma display panel according to claim 22 , wherein the preheating step is performed in a reduced pressure atmosphere. 26. The dry gas has a water vapor partial pressure of 15 To in an atmosphere in which it is used.
It is below rr, It is characterized by the above-mentioned 1-5,16-.
23. A method of manufacturing a plasma display panel according to any one of 18 and 22 . 27. The dew point temperature of the dry gas is 20 ° C. or lower, and the dew point temperature is 1 to 5, 16 to 18, 2.
3. The method for manufacturing a plasma display panel according to any one of 2 . The method according to claim 28 wherein said dry gas, claim, characterized in that oxygen is contained 1～5,1
23. The method for manufacturing a plasma display panel according to any one of 6 to 18 , 22 . 29. The dry gas, claim, characterized in that a dry air 1～5,16～
23. A method of manufacturing a plasma display panel according to any one of 18 and 22 .