JP2007317488A - Method and device for manufacturing plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a plasma display panel capable of suppressing rise of discharge voltage due to impurity gas. <P>SOLUTION: Since a forming process to a sealing process of a protection film are carried out in an atmosphere in which the concentration of remaining water is 10.6 ppm or less, rise of discharge voltage can be suppressed even when an impurity gas is adsorbed in the protection film. Furthermore, the forming process to the sealing process of the protection film can be carried out without reducing pressure necessarily, a large scale vacuum device is not required, and the time required for manufacture can be shortened to give a further benefit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma display panel manufacturing method and a plasma display panel manufacturing apparatus.

  A plasma display panel (PDP) includes a front substrate on which sustain electrodes and scan electrodes are formed, and a rear substrate on which address electrodes and phosphors are formed. Both substrates are bonded together by a sealing material disposed at the peripheral edge, and a discharge gas is sealed between the substrates. When a voltage is applied between the electrodes, the discharge gas is turned into plasma and ultraviolet rays are emitted. The ultraviolet rays are incident on the phosphor to excite the phosphor and emit visible light.

  The sustain electrodes and the scan electrodes are covered with a dielectric layer, and a protective film is formed so as to cover the dielectric layer. This protective film protects the dielectric layer from cations generated by turning the discharge gas into plasma, and a protective film made of MgO is generally known. It is known that the voltage (discharge voltage) at the time of discharging the PDP depends on the secondary electron emission coefficient of the protective film. That is, it is known that the discharge voltage is lowered as the secondary electron emission coefficient of the protective film is larger (as the work function is smaller and electrons are more likely to be emitted).

When manufacturing such a PDP, a method is generally used in which a front substrate and a back substrate are separately formed and then both substrates are bonded together. In this manufacturing method, impurity gas such as H ₂ O and CO ₂ contained in the surrounding atmosphere is adsorbed to the protective film from the time when the protective film is formed on the front substrate to the time when the front substrate and the rear substrate are bonded together. There are many cases. In the state where these impurity gases are attached, the secondary electron emission coefficient of the protective film becomes small, and there is a possibility that the discharge voltage becomes high when the PDP is discharged. For this reason, the surroundings of the front substrate and the rear substrate are set in a vacuum atmosphere, and a protective film is formed and the two substrates are bonded together (see, for example, Patent Document 1).
JP 2002-56773 A

  However, even when the surroundings of the front substrate and the rear substrate are in a vacuum atmosphere, it is difficult to completely evacuate, and some residual gas is actually present. When the residual gas contains an impurity gas, the impurity gas may be adsorbed on the protective film and the discharge voltage may be increased.

  In view of the circumstances as described above, an object of the present invention is to provide a plasma display panel manufacturing method and a plasma display panel manufacturing apparatus capable of suppressing an increase in discharge voltage due to an impurity gas.

  In order to solve the above problems, a method of manufacturing a plasma display panel according to the present invention is a method of manufacturing a plasma display panel having a first substrate provided with a first electrode and a second substrate provided with a second electrode. A protective film forming step of forming a protective film on at least one of the first electrode and the second electrode; and after the protective film forming step, between the first substrate and the second substrate. A sealing step of bonding the first substrate and the second substrate so as to enclose a discharge gas, and a residual moisture concentration of 10.6 ppm from after the protective film forming step to the sealing step. It is characterized by being performed in the following atmosphere.

The present inventors have almost no influence on the discharge voltage even when an impurity gas (especially H ₂ O) is adsorbed on the protective film in an atmosphere having a residual moisture concentration of 10.6 ppm or less. I found out. Therefore, in the present invention, the process from the protective film formation process to the sealing process is performed in an atmosphere having a residual moisture concentration of 10.6 ppm or less, so even if the impurity gas is adsorbed on the protective film, An increase in discharge voltage can be suppressed. Further, in the present invention, since it is not necessary to make a vacuum between the protective film forming process and the sealing process, there is an advantage that a large-scale vacuum apparatus is not required and the time required for manufacturing can be shortened.

Moreover, it is preferable to further comprise an inert gas supply step of supplying an inert gas having a residual moisture concentration of 10.6 ppm or less to the periphery of the protective film after the protective film forming step and before the sealing step.
According to the present invention, the inert gas having a residual moisture concentration of 10.6 ppm or less is supplied around the protective film after the protective film forming step and before the sealing step. An atmosphere having a residual moisture concentration of 10.6 ppm or less can be obtained.

In the inert gas supply step, it is preferable to supply the inert gas so as to circulate over the protective film.
The impurity gas adsorbed on the protective film may be released to the surroundings again depending on the ambient temperature or the like. If the inert gas stays on the protective film, the impurity gas released around the protective film may be adsorbed on the protective film again. According to the present invention, in the inert gas supply step, since the inert gas is supplied so as to circulate on the protective film, the inert gas can be prevented from staying on the protective film. Thereby, it can prevent more reliably that impurity gas adsorb | sucks to a protective film.

  The plasma display panel manufacturing apparatus according to the present invention is a plasma display panel manufacturing apparatus having a first substrate provided with a first electrode and a second substrate provided with a second electrode, wherein the first electrode A protective film forming part for forming a protective film on at least one of the upper electrode and the second electrode; and the first substrate and the second substrate so that a discharge gas is sealed between the first substrate and the second substrate. At least one of a sealing portion for bonding the second substrate, a connecting portion connecting the protective film forming portion and the sealing portion, and the connecting portion and the sealing portion has a residual moisture concentration of 10. And an atmosphere adjusting means for adjusting to an atmosphere of 6 ppm or less.

  According to the present invention, the discharge gas is sealed between the first substrate and the second substrate, and the protective film forming portion for forming the protective film on at least one of the first electrode and the second electrode. At least one of the sealing part for bonding the first substrate and the second substrate, the connecting part for connecting the protective film forming part and the sealing part, and the connecting part and the sealing part, Since the atmosphere adjusting means for adjusting the atmosphere having a residual moisture concentration of 10.6 ppm or less is provided, a plasma display panel in which the discharge voltage is unlikely to increase can be manufactured.

In addition, the atmosphere adjusting means includes an inert gas supply mechanism that supplies an inert gas having a residual moisture concentration of 10.6 ppm or less to the connecting portion and the sealing portion, and the inert gas is supplied to the connecting portion and the sealing portion. It is preferable to have an inert gas discharge mechanism that discharges from the landing portion.
According to the present invention, the atmosphere adjusting means has the inert gas supply mechanism for supplying the inert gas having a residual water concentration of 10.6 ppm or less to the connection portion and the sealing portion, so that the inside of the connection portion and the sealing portion are surely provided. In an atmosphere having a residual moisture concentration of 10.6 ppm or less.

Moreover, it is preferable that the said atmosphere adjustment means has an inert gas discharge mechanism which discharges | emits the said inert gas from the said connection part and the said sealing part.
According to the present invention, since the inert gas discharge mechanism that discharges the inert gas from the connection portion and the sealing portion is provided, the inert gas in the connection portion and the sealing portion can be exhausted. By operating the inert gas supply mechanism and the inert gas discharge mechanism, the inert gas circulates in the connection portion and the sealing portion from the inert gas supply mechanism to the inert gas discharge mechanism. Thereby, it can avoid that the inert gas in a connection part and a sealing part retains.

  According to the present invention, the process from the protective film forming process to the sealing process is performed in an atmosphere having a residual moisture concentration of 10.6 ppm or less. Therefore, even when the impurity gas is adsorbed on the protective film, An increase in discharge voltage can be suppressed. Further, since it is not always necessary to reduce the pressure, there is an advantage that a large vacuum apparatus is not necessary and the time required for the production can be shortened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.
(Plasma display panel)
FIG. 1 is an exploded perspective view of a three-electrode AC type plasma display panel.
In a plasma display panel (PDP) 100, a back substrate (first substrate) 1 and a front substrate (second substrate) 2 are disposed to face each other, and a plurality of discharge chambers 16 are provided between the back substrate 1 and the front substrate 2. It is the composition which has.

  On the inner surface of the back substrate 1 (the surface facing the front substrate 2), a plurality of address electrodes (first electrodes) 11 are arranged in stripes at predetermined intervals. A dielectric layer 19 is provided on the surface of the plurality of address electrodes 11. The dielectric layer 19 is provided on the entire surface of the back substrate 1 including the address electrodes 11, and the surface of the dielectric layer 19 is flat.

  Partitions (ribs) 15 are provided in the region between adjacent address electrodes 11 on the surface of the dielectric layer 19 along the extending direction of the address electrodes 11. A phosphor 17 that emits red, green, or blue fluorescence is disposed between the adjacent barrier ribs 15 so as to cover the upper surface of the dielectric layer 19 and the side surfaces of the barrier ribs 15, respectively.

  On the other hand, on the inner surface of the front substrate 2 (the surface facing the rear substrate 1), the scanning electrodes 12a and the sustain electrodes 12b constituting the display electrode (second electrode) 12 are alternately arranged in stripes at predetermined intervals. ing. The display electrode 12 is made of a transparent conductive material such as ITO, and extends in a direction orthogonal to the address electrode 11. The intersection of the address electrode 11 and the display electrode 12 is a pixel of the PDP 100. At the intersection, the distance (discharge gap) between the address electrode 11 and the display electrode 12 is about 80 μm.

  A dielectric layer 13 is formed on the display electrode 12 so as to cover the display electrode 12 and the inner surface of the front substrate 2. A protective film 14 is formed on the dielectric layer 13 so as to cover the dielectric layer 13. The protective film 14 protects the dielectric layer 13 from cations generated by turning the discharge gas into plasma, and contains MgO as a main component. By including MgO as a main component, the protective film 14 having high sputtering resistance is obtained. The thickness of the protective film 14 is about 8000 mm.

  The rear substrate 1 and the front substrate 2 thus configured are bonded together by, for example, a sealing material, and a discharge chamber 16 is formed between adjacent barrier ribs 15. Inside the discharge chamber 16, a discharge gas such as a mixed gas of Ne and Xe is sealed at a pressure of about 400 Torr. The discharge gas contains about 4% by volume of Xe gas.

  When lighting the pixel, a DC voltage is applied between the address electrode 11 and the scan electrode 12a to generate a counter discharge, and an AC voltage is further applied between the scan electrode 12a and the sustain electrode 12b. Generate a discharge. The discharge gas sealed in the discharge chamber 16 is turned into plasma by discharge, and vacuum ultraviolet rays are emitted. The phosphor 17 is excited by the ultraviolet rays, and visible light is emitted from the front substrate 2. The discharge voltage at this time is called the first cell lighting voltage.

(Plasma display panel manufacturing equipment)
Next, the PDP manufacturing apparatus according to the present embodiment will be described with reference to FIG.
As shown in the figure, a PDP manufacturing apparatus 30 introduces a front substrate 2 and a rear substrate 1 and manufactures a PDP 100 by vacuum processing, and includes a front substrate load chamber 31, a vapor deposition chamber (protective film forming section). 32, a cooling chamber (connection portion) 33, a rear substrate load chamber 34, a rear substrate degas chamber 35, a transfer chamber (connection portion) 36, an alignment / sealing chamber (sealing portion) 37, and an unload chamber 38. ing. The inner wall of each chamber is made of stainless steel.

  In the vapor deposition chamber 32 and the back substrate degassing chamber 35, for example, a vacuum exhaust mechanism 46 such as a rotary pump or a turbo molecular pump for making the chamber into a vacuum atmosphere is attached. In the cooling chamber 33, the transfer chamber 36, and the alignment / sealing chamber 37, an inert gas supply mechanism 48 that supplies an inert gas and an inert gas discharge mechanism 49 that discharges the inert gas from these chambers are attached. (Atmosphere adjusting means). As the inert gas, for example, dry nitrogen gas, dry argon gas, dry xenon gas, or the like can be used. All the inert gases are dried to a residual water concentration of 10.6 ppm (dew point -60 ° C.) or less. The reason why the residual water concentration is 10.6 ppm or less will be described in detail in [Example].

The front substrate load chamber 31 is a space for carrying the front substrate 2 and is connected to the vapor deposition chamber 32. A transport mechanism (not shown) for transporting the front substrate 2 carried into the front substrate load chamber 31 to the vapor deposition chamber 32 is provided.
The vapor deposition chamber 32 is a space for depositing the protective film 14 on the front substrate 2 and is connected to the front substrate load chamber 31 and the cooling chamber 33 described above. In the vapor deposition chamber 32, a heating mechanism for heating the front substrate 2, an evaporating material mainly composed of MgO, and an electron beam gun for irradiating the evaporating material with an electron beam are arranged. The evaporation material can be evaporated by irradiating the evaporation material with an electron beam. The vapor deposition chamber 32 is provided with an oxygen gas introduction mechanism that introduces oxygen gas into the vapor deposition chamber 32 during vapor deposition.

  The cooling chamber 33 is a space for cooling the front substrate 2 heated in the vapor deposition chamber 32, and is connected to the vapor deposition chamber 32 and the transfer chamber 36 described above. The cooling chamber 33 is provided with a support base for supporting the front substrate 2 and a cooling mechanism provided above the support base. A control unit (not shown) is provided in the cooling mechanism so that the substrate temperature of the front substrate 2 supported by the support base can be cooled and controlled to a predetermined temperature.

The rear substrate load chamber 34 is a space for carrying the rear substrate 1 and is connected to the rear substrate degas chamber 35. A transport mechanism (not shown) for transporting the back substrate 1 carried into the back substrate load chamber 34 to the back substrate degassing chamber 35 is provided.
The back substrate degassing chamber 35 is a space for heating the back substrate 1 and removing gas (such as water vapor) adsorbed on the back substrate 1, and is connected to the back substrate loading chamber 34 and the transfer chamber 36 described above. . A heating mechanism 46 for heating the back substrate 1 is provided in the back substrate degassing chamber 35.

  The transfer chamber 36 is connected to the cooling chamber 33 and the back substrate degas chamber 35 described above, and is a space where the front substrate 2 from the cooling chamber 33 and the back substrate 1 from the back substrate degas chamber 35 merge. . The transfer chamber 36 is also connected to an alignment / sealing chamber 37 and is a space for transferring the joined front substrate 2 and rear substrate 1 to the alignment / sealing chamber 37. The transfer chamber 36 is also connected to an unload chamber 38 and is a space for transferring the PDP 100 from the alignment / sealing chamber 37 to the unload chamber 38. For this reason, the transfer chamber 36 is provided with a transfer robot (not shown) for transferring the front substrate 2, the rear substrate 1 and the PDP.

  The alignment / sealing chamber 37 positions the front substrate 2 and the rear substrate 1, seals both substrates, and encloses the discharge gas between the front substrate 2 and the rear substrate 1 to complete the PDP 100. Space. The alignment / sealing chamber 37 is connected to the transfer chamber 36 described above.

The alignment / sealing chamber 37 is provided with a positioning mechanism for positioning the front substrate 2 and the rear substrate 1 and a discharge gas supply unit for supplying a discharge gas. The alignment / sealing chamber 37 is provided with a discharge gas purifier 47 for purifying the discharge gas diffused in the chamber so that the discharge gas purified by the discharge gas purifier 47 can be reused. It has become.
The unload chamber 38 is a space for taking out the PDP 100 completed in the alignment / sealing chamber 37 to the outside, and is connected to the transfer chamber 36 described above.

(Plasma display panel manufacturing method)
Next, a method for manufacturing the PDP 100 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a flow of manufacturing the PDP 100 according to the present embodiment. In this embodiment, the front substrate 2 and the rear substrate 1 are formed separately, and the PDP 100 is manufactured by a procedure in which both substrates are bonded.

A procedure for forming the front substrate 2 will be described.
First, the display electrode 12 and the dielectric layer 13 are formed on the front substrate 2 (ST11). In this state, the front substrate 2 is carried into the front substrate load chamber 31 of the PDP manufacturing apparatus 30. When the front substrate 2 is carried in, the transport mechanism in the front substrate load chamber 31 transports the front substrate 2 to the vapor deposition chamber 32.

In the vapor deposition chamber 32, the protective film 14 is formed (ST12: protective film forming step).
First, the inside of the vapor deposition chamber 32 is evacuated by the evacuation mechanism 46. When the inside of the vapor deposition chamber 32 is evacuated, oxygen gas is supplied into the vapor deposition chamber 32 by an oxygen gas supply mechanism, and the partial pressure of the oxygen gas is controlled to be about 3.0 × 10 ⁻² Pa. At the same time, the substrate temperature of the front substrate 2 is adjusted to about 250 ° C.

  When the evaporation material is evaporated by irradiating the electron beam from the electron beam gun toward the evaporation material while adjusting the partial pressure of the oxygen gas and the substrate temperature of the front substrate 2, the evaporated evaporation material passes through the vapor deposition chamber 32. It circulates as a vapor flow and deposits on the front substrate 2 at a film formation rate of about 40 Å / s. The deposit of the evaporation material becomes the protective film 14.

After the protective film 14 is formed, the inert gas supply mechanism 48 and the inert gas exhaust mechanism 49 cause the residual moisture concentration in the cooling chamber 33, the transfer chamber 36, and the alignment / sealing chamber 37 to be 10.6 ppm or less. Gas is circulated (ST13: inert gas supply step). After the inert gas is circulated, the front substrate 2 is transferred onto the support base of the cooling chamber 33. In the cooling chamber 33, the front substrate 2 heated during vapor deposition is cooled to a predetermined temperature by a cooling mechanism in an inert gas atmosphere (ST14).
In this way, the front substrate 2 is formed. The front substrate 2 is transferred to a transfer chamber 36 in an inert gas atmosphere having a residual moisture concentration of 10.6 ppm or less.

Next, a procedure for forming the back substrate 1 will be described.
First, the address electrode 11, the dielectric layer 19, the partition wall 15, and the phosphor 17 are formed on the inner surface of the back substrate 1 (ST21), and a sealing material (not shown) is further formed (ST22). In this state, it is carried into the rear substrate load chamber 34 of the PDP manufacturing apparatus 30. When the back substrate 1 is carried in, the transfer mechanism in the back substrate load chamber 34 transfers the back substrate to the degas chamber 35. In the degassing chamber 35, the back substrate 1 is heated in vacuum to perform a degassing process on the sealing material formed on the inner surface of the back substrate 1 (ST23).
In this way, the back substrate 1 is formed. After the degassing process, the rear substrate 1 is transferred to the transfer chamber 36.

  Next, the front substrate 2 and the rear substrate 1 are carried into the alignment / sealing chamber 37 having an inert gas atmosphere with a residual moisture concentration of 10.6 ppm or less, and the front substrate 2 and the rear substrate 1 are bonded together. Positioning is performed (ST31). When the positioning is completed, the inert gas in the alignment / sealing chamber 37 is discharged and a vacuum atmosphere is established (ST32).

When the inert gas is discharged, the discharge gas is introduced into the alignment / sealing chamber 37 (ST33). When the discharge gas is introduced, the sealing material is heated to bond the front substrate 2 and the rear substrate 1 together (ST34). When the bonding is completed, the sealing material is cured, and the front substrate 2 and the rear substrate 1 are sealed with the discharge gas sealed between the front substrate 2 and the rear substrate 1 (ST35). Thus, the sealing process is performed in the alignment / sealing chamber 37 to obtain the PDP 100. After the sealing step, the discharge gas is taken in by the discharge gas purifier 47 and made reusable.
Thereafter, the PDP 100 is transferred to the unload chamber 38 via the transfer chamber 36 and taken out from the unload chamber 38.

  According to the present embodiment, the process from the protective film forming process to the sealing process is performed in an atmosphere having a residual moisture concentration of 10.6 ppm or less. However, it is possible to suppress an increase in discharge voltage. Further, since it is not always necessary to reduce the pressure from the protective film forming step to the sealing step, there is an advantage that a large vacuum device is not required and the time required for the production can be shortened.

The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, xenon gas is exemplified as the inert gas. However, since xenon gas is very expensive, in addition to the alignment / sealing chamber 37, the cooling chamber 33 for circulating the inert gas, the transfer The chamber 36 may have a gas recovery mechanism. Thereby, expensive xenon gas can be recovered and reused, and cost reduction can be realized.

  Moreover, in the said embodiment, although MgO was used as a material of the protective film 14, it is not restricted to this. For example, SrO, CaO, or a mixture thereof may of course be used. By using SrO, the discharge voltage can be further reduced. Moreover, by using CaO, it is possible to improve the sputtering resistance while lowering the discharge voltage.

  Next, an example will be described in which a thin film mainly composed of MgO is exposed in CDA (Clean Dry Air) having a different dew point, and the amount of gas released from the exposed thin film is measured. FIG. 4 is a conceptual diagram of the measuring apparatus used in this example. FIG. 5 is a graph showing the temperature change around the MgO thin film in the measurement performed in this example. The vertical axis is temperature, and the horizontal axis is time.

In this embodiment, as shown in FIGS. 4 and 5, an MgO thin film 102 is formed on a stainless steel substrate (SUS304) 101 and placed in the pre-baking chamber 100, and first heated at 450 ° C. for 20 minutes by the lamp heater 103. Then, the MgO thin film 102 was degassed. The size of the stainless steel substrate 101 is 1050 mm × 650 mm. The film thickness of the MgO thin film 102 was set to 1 μm, 50 μm, and 100 μm, and the area of the formation region of the MgO thin film 102 was unified to 0.63 m ² .

Next, after naturally cooling to about 60 ° C., CDA having different humidity was introduced into the pre-baking chamber 100 and exposed for about 10 minutes. Regarding the humidity of CDA, dew point -70 ° C. (absolute humidity 1 mg / m ₃ ), dew point −60 ° C. (absolute humidity 10 mg / m ₃ ), dew point −40 ° C. (absolute humidity 100 mg / m ₃ ), relative humidity 52% air The relative humidity was 45% air. Note that the relative humidity in the state where the inside of the PDP manufacturing apparatus 30 described in the above embodiment is a clean room is 52%.

  After the exposure, the inside of the pre-bake chamber 100 was heated at 250 ° C., and gas was released for about 12 minutes. As a comparative example, the same measurement was performed using a stainless steel substrate on which no MgO thin film was formed.

  FIG. 6 is a graph showing the relationship between the thickness of the MgO thin film and the pressure of the QMS used for measurement of the released gas. The vertical axis is pressure (unit is Pa), and the horizontal axis is time (unit is min). As shown in FIG. 6, (1) in the case of air having a film thickness of 100 μm and humidity of 52%, (2) in the case of CDA having a film thickness of 100 μm and a dew point of −70 ° C. In the case of CDA at 40 ° C. (4) In the case of CDA having a film thickness of 50 μm and dew point of −40 ° C., (5) In the case of CDA having a film thickness of 10 μm and dew point of −40 ° C. ) And the humidity is 45%. From the graph of FIG. 6, it was confirmed that the amount of gas released increases as the thickness of the MgO thin film increases.

FIG. 7 is a logarithmic graph showing the relationship between the dew point (absolute humidity) of the gas introduced into the pre-baking chamber 100 and the total amount of gas released from the MgO thin film 102. The vertical axis represents the total gas release amount (unit: Pa), and the horizontal axis represents the dew point (absolute humidity). The unit of the horizontal axis is the unit of absolute humidity mg / m ₃ .

  The broken line L in FIG. 7 indicates the total amount of gas released when the stainless steel substrate 101 not formed with the MgO thin film is exposed to the atmosphere with a relative humidity of 52%. When this discharge amount is 1, the total gas discharge amount when the MgO thin film 102 is 100 μm is about twice at a dew point of −40 ° C. and about 0.7 times at a dew point of −60 ° C. From this result, it was confirmed that at the dew point of −60 ° C., the total amount of gas released from the MgO thin film 102 was smaller than that of the stainless steel substrate 101 exposed to the atmosphere having a relative humidity of 52%.

In the said embodiment, the inner wall of the PDP manufacturing apparatus 30 is formed with stainless steel. If the inside of the PDP manufacturing apparatus 30 is in an atmosphere having a dew point of −60 ° C. or lower, it can be said that the adhesion of impurity gas (particularly H ₂ O) is less than that in a normal clean room. The residual water concentration in an atmosphere with a dew point of −60 ° C. is 10.6 ppm. Therefore, if the residual moisture concentration in the PDP manufacturing apparatus 30 is 10.6 ppm or less, the adhesion of impurity gas (especially H ₂ O) is less than that in the clean room, so even if the impurity gas is adsorbed on the protective film 14. It can be said that the discharge voltage is not affected.

The perspective view which shows the structure of PDP which concerns on embodiment of this invention. The top view which shows the structure of the PDP manufacturing apparatus which concerns on this embodiment. The flowchart which shows the manufacturing process of PDP which concerns on this embodiment. The figure which shows the structure of the experimental apparatus which concerns on the Example of this invention. The figure which shows the mode of the temperature change around a MgO thin film in a present Example. In the present Example, the graph which shows the relationship between gas discharge time and gas discharge amount. In this example, a logarithmic graph showing the relationship between the dew point of gas and the total amount of gas released.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Back substrate 2 ... Front substrate 11 ... Address electrode 12 ... Display electrode 12a ... Scan electrode 12b ... Sustain electrode 13 ... Dielectric layer 14 ... Protective film 16 ... Discharge chamber 30 ... PDP manufacturing apparatus 32 ... Deposition chamber 36 ... Transfer chamber 37 ... Alignment / sealing chamber 48 ... Inert gas supply mechanism 49 ... Inert gas exhaust mechanism 100 ... PDP

Claims (6)

A method of manufacturing a plasma display panel having a first substrate provided with a first electrode and a second substrate provided with a second electrode,
A protective film forming step of forming a protective film on at least one of the first electrode and the second electrode;
A sealing step of bonding the first substrate and the second substrate so that a discharge gas is sealed between the first substrate and the second substrate after the protective film forming step;
A method for manufacturing a plasma display panel, wherein the process from the protective film forming step to the sealing step is performed in an atmosphere having a residual moisture concentration of 10.6 ppm or less. The method further comprises an inert gas supply step of supplying an inert gas having a residual moisture concentration of 10.6 ppm or less to the periphery of the protective film before the sealing step after the protective film forming step. Item 2. A method for manufacturing a plasma display panel according to Item 1. The method for manufacturing a plasma display panel according to claim 2, wherein in the inert gas supply step, the inert gas is supplied so as to flow over the protective film. An apparatus for manufacturing a plasma display panel having a first substrate provided with a first electrode and a second substrate provided with a second electrode,
A protective film forming part for forming a protective film on at least one of the first electrode and the second electrode;
A sealing portion for bonding the first substrate and the second substrate so that a discharge gas is sealed between the first substrate and the second substrate;
A connecting portion for connecting the protective film forming portion and the sealing portion;
An apparatus for manufacturing a plasma display panel, comprising: atmosphere adjusting means for adjusting at least one of the connection portion and the sealing portion to an atmosphere having a residual moisture concentration of 10.6 ppm or less.   5. The plasma display according to claim 4, wherein the atmosphere adjusting unit includes an inert gas supply mechanism that supplies an inert gas having a residual moisture concentration of 10.6 ppm or less to the connection portion and the sealing portion. Panel manufacturing equipment. 6. The apparatus for manufacturing a plasma display panel according to claim 5, wherein the atmosphere adjusting means has an inert gas discharge mechanism for discharging the inert gas from the connection part and the sealing part.

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