JP2009224092A - Manufacturing method of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a PDP capable of enhancing exhausting capacity of impurity gas existing in a panel. <P>SOLUTION: Among the manufacturing method of the PDP including a sealing process for sealing between a first substrate and a second substrate arranged in opposition so as to form a discharge space in between with a sealing material arranged at a peripheral part, the sealing process includes steps of softening the sealing material by carrying out first temperature raising from an ambient temperature to a softening point while introducing drying gas into a space between the first and the second substrates, melting the sealing material by carrying out second temperature raising from the softening point to a melting temperature by controlling introduction of drying gas into the space and exhaustion after the first temperature raising while the first and the second substrates are alternatively deformed to flat non-elastic deforming positions of each other and elastic deforming positions warping into convex shapes in a separating direction with each other, solidifying the sealing material by lowering the temperature from the melting one to one below the softening point after the second temperature raising, and sealing the discharge gas in the space after exhaustion after lowering of the temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a plasma display panel, and more particularly to a method for exhausting impure gas existing in a panel.

  A plasma display panel (hereinafter referred to as PDP) can realize high definition and a large screen, and is used for an image display device such as a large-sized television of 65 inches or more.

  The PDP has a structure in which a front plate and a back plate are arranged to face each other and a peripheral portion is sealed with a sealing material for sealing. A discharge space is formed between the front plate and the back plate, and discharge gas such as Ne (neon) and Xe (xenon) is sealed in the discharge space. The front plate includes a plurality of display electrodes formed on one surface of the glass substrate, a dielectric layer that covers these display electrodes, and a dielectric protective layer that covers the dielectric layer. The back plate includes a plurality of address electrodes formed on one surface of the glass substrate, a base dielectric layer covering these address electrodes, a partition formed to partition the discharge space for each address electrode, and a partition And a phosphor layer of red, green, and blue that are sequentially applied to a groove formed by the side surface and the base dielectric layer. The display electrode and the address electrode are orthogonal to each other, and the intersection is a discharge cell. These discharge cells are arranged in a matrix, and the three discharge cells having red, green, and blue phosphor layers arranged in the extending direction of the display electrodes are pixels for color display. The PDP sequentially displays a color image by applying a predetermined voltage between the electrodes to generate a gas discharge and exciting the phosphor layer with ultraviolet rays generated by the gas discharge to emit visible light. it can.

  Conventionally, magnesium oxide is often used as a material for the dielectric protective layer of the front plate. However, a metal oxide such as magnesium oxide has a property of adsorbing an impure gas such as water or carbon dioxide and easily forming a hydroxide compound or a carbonate compound. For this reason, in the manufacturing process of the PDP having the above-described structure, when the dielectric protective layer is formed and the processes such as the alignment of the front plate and the back plate, the substrate transport, and the sealing are performed in the air, Water molecules may become impure gas. In this case, the water molecules are adsorbed on the dielectric protective layer, and the water molecules react with the material of the dielectric protective layer to form a hydroxide compound or a carbonate compound. Hydroxide compounds and carbonic acid compounds have lower secondary electron emission efficiency than the original metal oxides. For this reason, there arises a problem that the discharge start voltage is increased, the discharge efficiency and the light emission efficiency are decreased, and the spatter resistance is decreased and the reliability is decreased. Therefore, it is necessary to remove water molecules adsorbed on the dielectric protective layer before reacting with the material of the dielectric protective layer.

  On the other hand, recently, as a material for the dielectric protective layer of the front plate, an alkaline earth metal oxide (for example, calcium oxide) whose secondary electron emission efficiency is higher than that of magnesium oxide in order to reduce the operating voltage of the PDP. , Strontium oxide, barium oxide, etc.) have been proposed. However, since these alkaline earth metal oxides have higher hygroscopicity than magnesium oxide, it is better to use an alkaline earth metal oxide than magnesium oxide as a dielectric protective layer to remove impure gas. It is difficult.

  As a method for solving the above problem, when sealing between a front plate and a back plate by melting and solidifying a sealing material for sealing, a glass tube is provided between the front plate and the back plate at a predetermined timing. There is a method of removing adsorbed impure gas by introducing a dry gas through (see, for example, Patent Document 1).

  13-15 is explanatory drawing which shows typically the manufacturing process of PDP of a prior art example. Here, the front plate and the back plate are arranged to face each other, and the sealing material before sealing is arranged on the periphery thereof is referred to as “panel”. In addition, after the sealing material for sealing is melted and solidified, a discharge gas sealed between the front plate and the back plate is referred to as “PDP”.

First, the initial setting state will be described with reference to FIG.
In FIG. 13, the front plate 110 and the back plate 120 constituting the panel 101 are arranged so that the surfaces on the side where electrodes (display electrodes, address electrodes) are formed are opposed to each other. A sealing material 130 for sealing such as glass is disposed. The front plate 110 and the back plate 120 are urged and fixed by a leaf spring 141 so as to be in close contact with a predetermined gap through a sealing material 130 for sealing. The panel 101 configured in this manner is disposed in a heating furnace 148 that heats the panel 101 with a predetermined temperature profile.

  The first and second glass tubes 142 and 143 are connected to the back plate 120 so as to communicate with the inside of the panel 101. The first glass tube 142 passes through the heating furnace 148 and is connected to the exhaust device 145 via the exhaust valve 144. The second glass tube 143 passes through the heating furnace 148 and is connected to the dry gas introduction device 147 through the gas supply valve 146. A sealing material is provided between the first and second glass tubes 142 and 143 and the back plate 120 to ensure airtightness in the panel and the glass tube, and they are fixed by a leaf spring (not shown). Has been.

Next, the manufacturing process of the PDP will be described.
First, the inside of the heating furnace 148 is heated to raise the temperature of the panel 101 from room temperature (for example, about 25 ° C.) to the softening point temperature (for example, about 350 ° C.) of the sealing material 130 for sealing. During this time, the gas supply valve 146 is opened, and the dry gas 161 is introduced from the dry gas introduction device 147 into the panel 101 through the second glass tube 143. Thereby, as shown in FIG. 14, the pressure in the panel 101 is increased, and the front plate 110 and the back plate 120 are deformed so as to be convex in a direction away from each other. At this time, a fine gap (not shown) is generated between the sealing material 130 for sealing and the front plate 110 due to the roughness (unevenness) of the surface of the sealing material 130 for sealing. For this reason, impure gas such as water vapor existing in the panel 101 is pushed by the dry gas 161 introduced into the panel 101 and is discharged to the outside of the panel 101 through the fine gap. Thereby, it is suppressed that the pressure in the panel 101 becomes excessively high, and the pressure in the panel 101 is maintained in a state higher by, for example, about 1 kPa than the external pressure. On the other hand, outside air can be prevented from flowing into the panel 101 from a minute gap, and the inside of the panel 101 can be filled with the dry gas 161. Contrary to the above, when the pressure in the panel 101 is smaller than the external pressure, the impurity gas in the atmosphere flows into the panel 101 through a fine gap. For this reason, in the step of raising the sealing material 130 to the softening point temperature, the exhaust valve 144 should not be opened to reduce the pressure in the panel 101.

  Through the above steps, the impure gas existing in the panel 101 is replaced with the dry gas 161, and the residual organic components on the surface of the back plate 120 are burned and decomposed and discharged to the outside of the panel 101.

  Next, by heating the heating furnace 148, the temperature of the panel 101 is raised to a peak temperature (for example, about 450 ° C.) that is equal to or higher than the softening point temperature of the sealing material 130 for sealing, and the sealing material 130 for sealing is completely melted. Thereby, a fine gap is sealed by the melted sealing material 130 for sealing. At this time, since the sealing material 130 for sealing is not solidified, the gas supply valve 146 and the exhaust valve 144 are closed and dried in order to prevent the sealing material 130 from dissipating and cracking of the substrate. Gas 161 is not introduced and exhausted.

  Next, by heating the heating furnace 148, the temperature of the panel 101 is lowered from the peak temperature to the softening point temperature or lower of the sealing material 130 for sealing. Since the sealing material 130 for sealing solidifies below the softening point temperature, the gas supply valve 146 is kept closed, the dry gas 161 is not introduced, the exhaust valve 144 is opened, and the exhaust device 145 opens the first glass tube. The gas 162 in the panel 101 is exhausted through 142 as shown in FIG. As a result, an impurity gas such as water vapor is not confined in the panel 101 serving as a discharge space, and the residual impurity gas can be reduced.

  Next, a discharge gas is introduced into the panel 101 until a predetermined pressure is reached. Thereafter, the first and second glass tubes 142 and 143 are melted by a burner or the like to seal the hole to which they are connected. Thereby, the atmosphere of the discharge space in the panel 101 is fixed, and the manufacture of the PDP is completed.

  However, in the above-described conventional method, when the temperature in the heating furnace 148 is increased from room temperature to the softening point temperature of the sealing material 130 for sealing, the impure gas is discharged from a minute gap. If the flow rate of the dry gas 161 introduced into the 101 is excessively increased, the front plate 110 and the back plate 120 may be damaged due to an increase in pressure in the panel 101. Therefore, there is a limit to increasing the flow rate of the dry gas 161, and as a result, it is not possible to sufficiently secure the ability to replace the impure gas in the panel 101 with the dry gas 161.

  Further, in the above-described conventional method, even when the temperature in the heating furnace 148 is raised to the peak temperature, in order to prevent the sealing material 130 from sticking out and sucking outside the panel 101, Must be within a certain range. Further, in the process of raising the temperature to the peak temperature, since the fine gap is sealed, the dry gas 161 cannot be further introduced in order to make the pressure inside the panel 101 within a certain range. . Therefore, there has been a problem that gas replacement and exhaust are incomplete, resulting in unstable discharge characteristics.

  As a method for solving this problem, for example, there are methods disclosed in Patent Documents 2 and 3. In the method of Patent Document 2, one glass substrate is warped in a convex shape by using a difference in thermal expansion coefficient between the glass substrates of the front plate and the back plate or by vacuum-adsorbing one glass substrate. This is a method of ensuring a large conductance and improving the exhaust capacity of impure gas. Further, the method of Patent Document 3 controls the pressure in the panel to be higher than the pressure outside the panel, and ensures a large conductance by deflecting each substrate in a convex shape in a direction away from each other. It is a method to improve the exhaust capacity of the.

JP-A-5-234512 JP 2005-56732 A JP 2002-229468 A

  However, in the production of a PDP using an alkaline earth metal oxide as the dielectric protective layer, the impurity gas that alters the surface of the dielectric protective layer cannot be sufficiently removed even if each of the above methods is used.

  Further, in the method of different thermal expansion coefficients of one glass substrate and the other glass substrate in Patent Document 2, selection of the glass substrate is greatly restricted. In the panel sealing step, the panel temperature varies in a wide temperature range from room temperature to about 400 ° C. as described above. Since the amount of thermal expansion of the glass substrate changes depending on the temperature, the conductance cannot be secured constant during the panel sealing process, and as a result, the impure gas exhaust capacity is sufficiently secured. I can't.

  In addition, in the method of deforming a glass substrate by vacuum suction in Patent Document 2, naturally, a device for vacuum suction is separately required. Further, since heat treatment for sealing is performed while vacuum-adsorbing the glass substrate, the configuration of the apparatus for transporting and sealing the panel becomes extremely complicated, and it is not easy to realize.

  In the method of Patent Document 3, a chamber having a size that can completely accommodate the panel is required to control the pressure difference between the pressure inside the panel and the pressure outside the panel. Further, during the sealing step, the panel temperature changes greatly as described above, and the amount of impure gas released changes greatly according to the temperature. For this reason, it is necessary to accurately control the introduction amount of the dry gas, the exhaust in the chamber, the exhaust in the panel, and the like according to the change. In order to realize such control, the configuration of the apparatus for pressure control and sealing becomes extremely complicated, and realization is not easy.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and further improve the exhaust capacity of impure gas existing in the panel as compared with the conventional example, so that the discharge efficiency, light emission efficiency, and reliability of the PDP can be improved. An object of the present invention is to provide a method of manufacturing a PDP that can be improved.

In order to achieve the above object, the present invention is configured as follows.
According to the first aspect of the present invention, the space between the first substrate and the second substrate that are arranged to face each other so that a discharge space is formed between each other is sealed in the peripheral portion of the space. A plasma display panel manufacturing method including a sealing step of sealing with a wearing sealant,
The sealing step is
While introducing a dry gas into the space between the first and second substrates, the first temperature rise is performed from room temperature to the softening point temperature, and the sealing material disposed at the periphery is softened,
After the first temperature rise, by controlling the introduction of the dry gas into the space and the exhaust of the gas in the space, the first and second substrates are in a flat inelastic deformation position, The softening point temperature is higher than the softening point temperature while alternately elastically deforming at least one of the first and second substrates to an elastic deformation position that is convexly warped away from the other substrate. A second temperature rise is performed up to the melting temperature to melt the softened sealing material for sealing,
After the second temperature rise, the temperature is lowered from the melting temperature to a temperature lower than the softening point temperature, the melted sealing material for sealing is solidified, and the first and second substrates are sealed,
After exhausting the temperature, exhausting the space and then enclosing a discharge gas in the space;
A method for manufacturing a plasma display panel is provided.

  According to the second aspect of the present invention, the exhaust of the gas in the space during the second temperature increase is performed using the elastic force of at least one of the first and second substrates. A method for manufacturing a plasma display panel according to the first aspect is provided.

According to the third aspect of the present invention, during the second temperature increase,
Elastic deformation of the first and second substrates from the inelastic deformation position to the elastic deformation position is performed by introducing the dry gas into the space,
The elastic deformation of the first and second substrates from the elastic deformation position to the inelastic deformation position causes the gas in the space to flow by the elastic force of at least one of the first and second substrates. This is done by extruding and exhausting from the space.
A method for manufacturing a plasma display panel according to the first aspect is provided.

According to a fourth aspect of the present invention, any one of the first to third aspects, wherein the dry gas includes any one of N ₂ , He, Ne, Ar, Xe, Kr, and O _2. A method for manufacturing a plasma display panel as described in (1) is provided.

  According to the fifth aspect of the present invention, during the temperature drop, any one of the first to fourth aspects, wherein the first and second substrates are not elastically deformed alternately at the inelastic deformation position and the elastic deformation position. A method of manufacturing the plasma display panel according to any one of the above is provided.

  According to the sixth aspect of the present invention, the first temperature increase is performed by controlling the introduction of the dry gas into the space and the exhaust of the gas in the space, so that the inelastic deformation position and the elastic deformation are controlled. A method for manufacturing a plasma display panel according to any one of the first to fifth aspects, wherein the first and second substrates are alternately elastically deformed at a position.

  According to a seventh aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to any one of the first to sixth aspects, wherein the introduction of the dry gas is performed such that the flow rate is gradually increased. .

  According to the method of manufacturing a PDP according to the present invention, the first and second substrates are moved to the inelastic deformation positions by controlling the introduction of the dry gas into the space and the exhaust of the gas in the space. A second temperature rise from the softening point temperature to the melting temperature is performed while elastically deforming alternately to the elastic deformation position. Thereby, the pressure in the space can be suppressed within a pressure range that does not cause the sealing material to dissipate and the spacing between the panels does not vary, and the second temperature from the softening point temperature to the melting temperature can be reduced. Gas replacement can be performed even when the temperature is raised. The impure gas is most likely to be detached from the surface of the panel in the vicinity of the melting temperature. Therefore, it is possible to improve the discharge efficiency, light emission efficiency, and reliability of the PDP by further improving the exhaust capability of the impure gas existing in the panel as compared with the conventional example. In addition, this makes it possible to extend the life of the PDP.

Before continuing the description of the present invention, the same parts are denoted by the same reference numerals in the accompanying drawings.
The best mode for carrying out the present invention will be described below with reference to the drawings.

<< First Embodiment >>
Before describing the PDP manufacturing method according to the first embodiment of the present invention, first, a front plate and a second substrate, which are examples of a first substrate used in the PDP manufacturing method, will be described with reference to FIG. A basic structure of the back plate as an example will be described.

  In FIG. 1, a front plate 10 includes a front glass substrate 11 made of, for example, sodium borosilicate glass or lead glass. On one surface of the front glass substrate 11, a plurality of strip-like display electrodes 12 are arranged in parallel (formed in stripes). A dielectric layer 13 is disposed on one surface of the front glass substrate 11 so as to cover each display electrode 12 and functions as a capacitor. A dielectric protective layer 14 is formed on the dielectric layer 13 so as to cover the dielectric layer 13. The front plate 10 has elasticity so as to allow a certain degree of bending.

  In FIG. 1, the back plate 20 includes a back glass substrate 21 configured in the same manner as the front glass substrate 11. On one surface of the rear glass substrate 21, a plurality of strip-like address electrodes 22 are arranged in parallel (formed in stripes). A dielectric layer 23 is formed on one surface of the rear glass substrate 21 so as to cover each address electrode 22. On the dielectric layer 23, a plurality of partition walls 24 are formed in stripes. A phosphor layer 25 is applied to each of the groove portions 26 formed by the side surfaces of the partition walls 24, 24 adjacent to each other and the dielectric layer 23. The phosphor layer 25 includes a red phosphor layer 25a, a green phosphor layer 25b, and a blue phosphor layer 25c, which are sequentially formed in a direction orthogonal to the address electrodes 22. The back plate 20 has elasticity so as to allow a certain degree of bending.

  Next, the manufacturing method of the PDP according to the first embodiment of the present invention will be described with reference to FIGS. 2-4 is explanatory drawing which shows typically the manufacturing process of PDP concerning 1st Embodiment of this invention. FIG. 5 is a flowchart showing the manufacturing process of the PDP according to the first embodiment of the present invention. FIG. 6 is a diagram schematically showing a fine gap existing between the sealing material for sealing and the front plate. FIG. 7 is a view showing a temperature profile of the panel in the manufacturing process of the PDP. In addition, here, the front plate 10 and the back plate 20 are arranged to face each other, and the sealing material 30 for sealing before solidification is arranged on the periphery thereof is referred to as “panel”. Further, after the sealing material 30 for sealing is melted and solidified, a discharge gas sealed between the front plate 10 and the back plate 20 is referred to as “PDP”.

First, the initial setting state will be described with reference to FIG.
In FIG. 2, the front plate 10 and the back plate 20 constituting the panel 1 are arranged so that the surfaces on the electrode (display electrode 12, address electrode 22) formation side face each other and the electrodes are orthogonal to each other, A sealing material 30 for sealing such as low-melting glass is disposed around the periphery. The front plate 10 and the back plate 20 are urged and fixed by a plate spring 41 so as to be in close contact with each other through a sealing material 30 for sealing. The panel 1 configured in this manner is arranged in a heating furnace 48 that heats the panel 1 so as to have a temperature profile shown in FIG.

Further, the first and second glass tubes 42 and 43 are connected to the back plate 20 so as to communicate with the inside of the panel 1. The first glass tube 42 penetrates the heating furnace 48 and is connected to the exhaust device 45 via the exhaust valve 44. The second glass tube 43 passes through the heating furnace 48, is connected to the dry gas introduction device 47 through the gas supply valve 46, and is connected to the pressure relief valve 50. The opening / closing operation of the pressure relief valve 50 is controlled by the pressure control unit 49. A sealing material is provided between the first and second glass tubes 42 and 43 and the back plate 20 in order to ensure airtightness in the panel and the glass tube, and they are fixed by a leaf spring (not shown). Has been.
The devices 45 and 47, the valves 44 and 46, the heating furnace 48, and the pressure control unit 49 are connected to a main control unit (not shown), and their operations are performed by the control unit according to the temperature profile shown in FIG. Done under control.

Next, the manufacturing process of the PDP will be described.
First, in step S1, the inside of the heating furnace 48 is heated to change the temperature of the panel 1 from room temperature T1 (for example, about 25 ° C.) to the softening point temperature T2 (for example, about about 25 ° C.) of the sealing material 30 for sealing. The first temperature rise h1 is increased to 350 ° C.). During this first temperature increase, the gas supply valve 46 is opened, and the dry gas 61 is continuously introduced from the dry gas introduction device 47 into the panel 1 through the second glass tube 43. As a result, as shown in FIG. 3, the pressure in the panel 1 is increased, and the front plate 10 and the back plate 20 are convex in a direction away from each other from the flat inelastic deformation position 1 </ b> A (for example, one substrate). With respect to the center point, the elastic deformation is performed up to the elastic deformation position 1B that warps the distance from the inelastic deformation position 1A to the elastic deformation position 1B from 0.3 mm to 3 mm.

  At this time, a fine gap 31 is formed between the sealing material 30 for sealing and the front plate 10 as shown in FIG. For this reason, the impure gas such as water vapor existing in the panel 1 is pushed by the dry gas 61 introduced into the panel 1 and discharged to the outside of the panel 1 through the fine gap 31. Thereby, it is suppressed that the pressure in the panel 1 becomes excessively high, and the pressure in the panel 1 is maintained in a state higher by, for example, about 1 kPa than the external pressure. On the other hand, external air can be prevented from flowing into the panel 1 from the minute gaps 31, and the inside of the panel 1 can be filled with the dry gas 61. Contrary to the above, when the pressure in the panel 1 is smaller than the external pressure, the impure gas in the atmosphere flows into the panel 1 through the minute gap 31. For this reason, at the time of the first temperature increase, the exhaust valve 44 should not be opened to make the inside of the panel 1 in a reduced pressure state.

As the dry gas 61 used here may be any gas containing little water vapor, for _{example, N 2, He, Ne,} Ar, Xe, Kr, any one of _{O 2} that is used preferable. By using these gases, it is possible to effectively prevent the surface of the dielectric protective layer 14 from being altered by the impure gas. The gas concentration is preferably 1 ppm or less. The gas flow rate is preferably about 20 sccm to 10 SLM. If the flow rate is too small, external air may be mixed, and conversely, if the flow rate is too high, it is disadvantageous in terms of cost.

  Due to the first temperature increase, the impure gas existing in the panel 1 is replaced with the dry gas 61, and the residual organic components on the surface of the back plate 20 are burned and decomposed and discharged to the outside of the panel 1. The

  Next, in step S2, by heating the heating furnace 48, the temperature of the panel 1 is changed to a peak temperature T3 as an example of a melting temperature that is equal to or higher than the softening point temperature T2 of the sealing material 30 for sealing as shown in FIG. The second temperature increase h2 is increased to 450 ° C., and the sealing material 30 for sealing is completely melted. As a result, the fine gap 31 is sealed by the molten sealing material 30 for sealing. At this time, since the sealing material 30 for sealing is not solidified, when the high-pressure dry gas 61 is introduced into the panel 1 in this state, the sealing material 30 is dissipated and the front plate 10 and the back plate 20 are dissipated. There is a risk of variations in the interval.

  For this reason, the flow rate of the dry gas 61 is controlled and introduced into the panel 1 so that the inside of the panel 1 is within a pressure range of, for example, about 3 to 20 kPa so as not to cause problems such as dissipation of the sealing material. To do. Thereby, the inside of the panel 1 is in a pressurized state, and the panel 1 is elastically deformed to a swelled state as shown by a dotted line in FIG. 3, that is, to the elastic deformation position 1B.

  On the other hand, at this time, since the fine gap 31 is sealed by the molten sealing material 30, when the dry gas 61 is further introduced into the panel 1, the pressure in the panel 1 becomes high. This causes problems such as dissipation of the sealing material. For this reason, the pressure relief valve 50 is opened under the control of the pressure control unit 49, and excess gas 63 in the panel 1 is discharged to the outside. Thereafter, the gas supply valve 10 is closed and the introduction of the dry gas 61 is stopped. Thereby, the gas in which the dry gas 61 and the impure gas in the panel 1 are mixed is pushed by the elastic force of the panel 1 to return to the inelastic deformation position 1A, and the gas is discharged to the outside through the pressure relief valve 50. Is done. Thereafter, the panel 1 returns to the original flat state, that is, the inelastic deformation position 1A as shown by the solid line in FIG.

  In the first embodiment, the opening and closing of the gas supply valve 46 and the pressure relief valve 50 are controlled so that the panel 1 is elastically deformed alternately between the inelastic deformation position 1A and the elastic deformation position 1B. Thus, a sufficient amount of dry gas 61 is supplied into the panel 1 to discharge the impure gas in the panel 1 while suppressing the pressure in the panel 1 so as not to cause problems such as dissipation of the sealing material. It becomes possible. The impure gas is more easily detached from the surface of the panel 1 as the temperature is higher. For this reason, in this step S2, the impure gas can be exhausted more efficiently than in step S1. Note that the gas in the panel 1 can be exhausted by controlling the opening and closing of the exhaust valve 8. However, as in the first embodiment, it is easier to control the exhaust of the impure gas in the panel 1 by utilizing the elastic deformation of the panel 1.

  Next, in step S3, a first temperature drop h3 for lowering the temperature of the panel 1 from the peak temperature T3 to near the softening point temperature T2 of the sealing material 30 for sealing (lower than the softening point temperature T2) by heating the heating furnace 48 is performed. Do. Thereby, the sealing material 30 for sealing will be in the state solidified gradually.

  At this time, similarly to step S2, gas replacement can be performed by alternately elastically deforming the panel 1 at the inelastic deformation position 1A and the elastic deformation position 1B. In this case, the impure gas exhaust capability can be further improved. On the other hand, when the gas exchange for alternately elastically deforming the panel 1 is not performed, the following advantages are obtained. That is, when the gas exchange for alternately elastically deforming the panel 1 is performed as in step S2, the pressure in the panel 1 is instantaneously deformed between the inelastic deformation position 1A and the elastic deformation position 1B. It fluctuates greatly. Since the sealing material 30 for sealing is not yet solidified at the time of the first temperature drop, when there is the pressure fluctuation, as shown in FIG. 9, bubbles 32 are formed in the sealing material 30 for sealing. May occur. FIG. 9 is an enlarged view of a portion surrounded by a thick line in FIG. If the sealing sealing material 30 is solidified in a state where a plurality of the bubbles 32 are connected and penetrate the sealing sealing material 30, there is a risk of leading to a leak failure. Therefore, it is possible to reliably suppress the occurrence of a leak failure by not performing the gas exchange that alternately elastically deforms the panel 1. Further, it is possible to prevent impure gas from entering the panel 1 through the connected bubbles 32 after the panel 1 is sealed.

  Next, in step S4, a second temperature drop h4 for lowering the temperature of the panel 1 from the vicinity of the softening point temperature T2 (for example, about 330 ° C.) to a temperature lower than that by the heating of the heating furnace 48 is performed. Thereby, the sealing material 30 for sealing solidifies completely, and the front board 10 and the back board 20 are adhere | attached. Even in this state, it is possible to perform gas replacement such that the panel 1 is elastically deformed alternately between the inelastic deformation position 1A and the elastic deformation position 1B. Thereby, the exhaust capability of impure gas can be improved.

  Next, in step S5, the gas supply valve 46 is closed, the dry gas 61 is not introduced, the exhaust valve 44 is opened, and the gas 62 in the panel 1 is passed through the first glass tube 42 by the exhaust device 45 in FIG. Exhaust as shown. As a result, the impure gas such as water vapor is not confined in the panel 1 serving as the discharge space, and the residual impure gas can be reduced.

  Next, in step S6, a discharge gas is introduced into the panel 1 until a predetermined pressure is reached. Examples of the discharge gas include Xe (xenon), a mixed gas of Ne (neon) and Xe, or a mixture of these gases with He (helium). Thereafter, the first and second glass tubes 42 and 43 are melted by a burner or the like to seal the hole to which they are connected. Thereby, the atmosphere of the discharge space in the panel 1 is fixed, and the manufacture of the PDP is completed.

  In the PDP manufactured by such a manufacturing method, by controlling the introduction of the dry gas 61 into the panel 1 and the exhaust of the gas in the panel 1, the panel 1 is moved to the inelastic deformation position 1 </ b> A and the elastic deformation position 1 </ b> B. The second temperature increase h2 is performed from the softening point temperature T2 to the peak temperature T3 while elastically deforming alternately. As a result, the pressure in the space can be suppressed within a pressure range that does not cause the sealing material to dissipate and the spacing between the panels does not vary, and gas replacement is performed even during the second temperature rise. be able to. Therefore, it is possible to improve the discharge efficiency, the light emission efficiency, and the reliability of the PDP by further improving the exhaust capability of the impure gas existing in the panel 1 as compared with the conventional example. In addition, this makes it possible to manufacture a PDP that has little change in discharge voltage, luminance, etc. and has an excellent panel life even when the PDP is driven for a long time. Further, even when an alkaline earth metal oxide having a work function smaller than that of magnesium oxide (for example, calcium oxide, strontium oxide, barium oxide, etc.) is used as the dielectric protective layer 14, stable discharge characteristics can be obtained. . In addition, in the PDP manufactured by the above manufacturing method, there is almost no alteration layer on the surface of the dielectric protective layer 14 and the adsorption of impure gas to the surface of the back plate 20 is very small, so that aging is almost unnecessary, or There is an advantage that only a very short time is required.

  In addition, according to the method for manufacturing a PDP according to the first embodiment of the present invention, it is possible to suppress the deterioration of the light emission characteristics of the phosphor generated in the sealing process of the conventional example with a stable process, and the discharge characteristics are stable. Can be realized. Further, the dry gas 61 can be continuously introduced into the panel 1 without requiring a special jig, and the inside of the panel 1 can always be maintained in a dry gas atmosphere.

<< Second Embodiment >>
Next, a method for manufacturing a PDP according to the second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a flowchart showing a method of manufacturing a PDP according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in that step S11 is performed instead of step S1 in which the first temperature increase h1 is performed. Since the other points are the same as those in the first embodiment, overlapping description will be omitted, and differences will be mainly described.

  At the time of the first temperature rise, as described above, the excess of the dry gas 61 introduced into the panel 1 through the second glass tube 43 is discharged from the gap 31 (see FIG. 6). However, when continuously introducing the drying gas 61 as in the first embodiment, if the introduction pressure of the drying gas 61 is too high, for example, as shown in FIG. The flow rate may be constant. In this case, the dry gas 61 is not uniformly supplied into the panel 1, and the removal of the impure gas may be uneven, and there may be a portion where the impure gas remains in the panel 1. Accordingly, as a result, the impure gas discharge capability may be insufficient.

  Therefore, in the second embodiment, in step S11, the introduction of the dry gas 61 into the panel 1 and the exhaust of the gas in the panel 1 are controlled so that the panel is moved to the inelastic deformation position 1A and the elastic deformation position 1B. The first temperature increase h1 is performed while elastically deforming 1 alternately. When gas replacement is performed in this way, the dry gas 61 flows as follows. That is, when the dry gas 61 is introduced, the inside of the panel 1 is in a pressurized state, and the dry gas 61 is discharged from the gap 31 (see FIG. 6). On the other hand, when the introduction of the dry gas 61 is stopped and the pressure relief valve 50 is opened to discharge the gas in the panel 1, the panel 1 is elastically deformed from the elastic deformation position 1A to the inelastic deformation position 1B. The excess dry gas 61 flows as shown in FIG. 11B. That is, the dry gas 61 spreads radially from the center of the panel 1 and is discharged from the gap 31. Therefore, the impurity gas can be removed uniformly. As a result, the impure gas discharge capacity can be improved, the color unevenness and brightness unevenness of the PDP can be suppressed, and a PDP having excellent panel characteristics can be manufactured.

<< Third Embodiment >>
Next, a method for manufacturing a PDP according to the third embodiment of the present invention will be described. Since the third embodiment is the same as the first embodiment except for the following points, the overlapping description will be omitted, and differences will mainly be described.

  In the third embodiment, the dry gas 61 is introduced so that the flow rate gradually increases. More specifically, for example, the set flow rate of the dry gas supply device 11 is gradually increased while the pressure control unit 49 monitors the pressure in the panel 3. As a result, local and instantaneous pressure increase in the vicinity of the second glass tube 43 and overshooting of the flow rate of the dry gas 61 can be prevented, and problems such as cracking of the panel 1 and dissipation of the sealing material 30 for sealing can be prevented. Can be prevented. As a result, the defect rate in the manufacturing process of the PDP can be reduced and the yield can be improved.

  In addition, the following method is mentioned as a specific method of gradually increasing the set flow rate of the dry gas supply device 11. For example, it can be realized by gradually opening the gas supply valve 46 while continuously supplying the dry gas 61 from the dry gas supply device 11. It can also be realized by gradually opening the pressure relief valve 50 while continuously supplying the dry gas 61 from the dry gas supply device 11. In the latter case, the dry gas 61 is introduced as much as is allowed in the panel 1, and the inside of the panel 1 can always be kept at a slightly positive pressure. Thereby, it is possible to prevent impure gas from flowing into the panel 1 through the gap 31 from the outside. Further, by setting the conductance on the escape side larger than that on the gas introduction side, it is possible to prevent sudden pressure increase in the panel 1 due to the gas introduction. Thereby, defects, such as a crack of the panel 1, can be prevented. Furthermore, in addition to the control of the pressure relief valve 50, an MFC (mass flow controller) may be provided in the gas introduction line to control the flow rate. With such a configuration, the number of times of opening and closing the gas supply valve 46 and the pressure relief valve 50 can be reduced, and the life of the apparatus can be greatly extended.

  In addition, this invention is not limited to said each embodiment, It can implement in another various aspect. For example, the dielectric protective layer 14 is typically made of magnesium oxide, but may be one obtained by adding a trace amount of elements (silicon, aluminum, etc.) thereto. Generally, it is desirable to include at least one of magnesium oxide, calcium oxide, strontium oxide, and barium oxide. By using calcium oxide, strontium oxide, or barium oxide, a PDP with a low driving voltage can be realized.

  When glass frit is used as the sealing material 30 for sealing, the glass frit may be pre-fired after the glass frit is applied and before the alignment of the front plate 10 and the back plate 20. Further, when the phosphor layer 25 of the back plate 20 is formed, the phosphor layer 25 can be fired at the same time as the glass frit is temporarily fired without firing the phosphor layer 25 in advance.

  In the above description, two glass tubes 42 and 43 are used for gas introduction and exhaust, but as shown in FIG. 12, one glass tube 43 is used for gas introduction and exhaust for simplification of equipment. You may make it share a function. Even in this case, the procedure is the same as the manufacturing method described above. However, when priority is given to suppressing color unevenness, luminance unevenness, and the like of the PDP, it is preferable to use the two glass tubes 42 and 43 for gas introduction and exhaust as described above.

  In the above description, the surface discharge type PDP is exemplified. However, the present invention can be applied to all PDPs that require a heat process for sealing, such as a counter discharge type PDP.

  It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

Since the PDP manufacturing method according to the present invention can further improve the exhaust ability of the impure gas existing in the panel and improve the discharge efficiency, light emission efficiency, and reliability of the PDP,
For example, it is useful as an image display device used in the video equipment industry, information equipment industry, advertising equipment industry, industrial equipment and other industrial fields such as small to large thin televisions, high-definition televisions, or thin information equipment terminals. is there.

It is a perspective view which shows typically the basic structure of the front board and back board which are used for the manufacturing method of PDP concerning 1st Embodiment of this invention. It is explanatory drawing which shows typically the manufacturing process of PDP concerning 1st Embodiment of this invention. FIG. 3 is an explanatory diagram schematically showing a process following FIG. 2. FIG. 4 is an explanatory diagram schematically showing a process following FIG. 3. It is a flowchart which shows the manufacturing process of PDP concerning 1st Embodiment of this invention. It is explanatory drawing which shows typically the fine clearance gap which exists between the sealing material for sealing, and a front board. It is a graph which shows the temperature profile of the panel in the manufacturing process of PDP concerning 1st Embodiment of this invention. It is explanatory drawing which shows a mode when a panel is elastically deformed alternately by the inelastic deformation position and the elastic deformation position at the time of 1st temperature fall. FIG. 9 is an enlarged view of a portion surrounded by a thick line in FIG. 8. It is a flowchart which shows the manufacturing process of PDP concerning 2nd Embodiment of this invention. It is explanatory drawing which shows the example which a dry gas flows into one direction. It is explanatory drawing which shows a mode that a dry gas flows radially from the center part of a panel. In the manufacturing process of PDP concerning the modification of this invention, it is explanatory drawing which shows typically arrangement | positioning of each part and each apparatus at the time of making the glass tube for gas introduction and gas exhaustion connected to a backplate into one. . It is explanatory drawing which shows typically the manufacturing process of PDP concerning a prior art example. It is explanatory drawing which shows the process following FIG. 13 typically. It is explanatory drawing which shows the process following FIG. 14 typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Panel 10 Front plate 11 Front glass substrate 12 Display electrode 13 Dielectric layer 14 Dielectric protective layer 20 Back plate 21 Back glass substrate 22 Address electrode 23 Dielectric layer 24 Partition 25 Phosphor layer 26 Groove part 30 Sealing sealing material 31 Gap 32 Bubble 41 Leaf spring 42 First glass tube 43 Second glass tube 44 Exhaust valve 45 Exhaust device 46 Gas supply valve 47 Drying gas supply device 48 Heating furnace 49 Pressure control unit 50 Pressure relief valve 61 Drying gas 62, 63 Gas

Claims (7)

A sealing step of sealing a space between the first substrate and the second substrate, which are arranged so as to form a discharge space between each other, with a sealing material disposed in the periphery of the space. A method of manufacturing a plasma display panel comprising:
The sealing step is
While introducing a dry gas into the space between the first and second substrates, the first temperature rise is performed from room temperature to the softening point temperature, and the sealing material disposed at the periphery is softened,
After the first temperature rise, by controlling the introduction of the dry gas into the space and the exhaust of the gas in the space, the first and second substrates are in a flat inelastic deformation position, The softening point temperature is higher than the softening point temperature while alternately elastically deforming at least one of the first and second substrates to an elastic deformation position that is convexly warped away from the other substrate. A second temperature rise is performed up to the melting temperature to melt the softened sealing material for sealing,
After the second temperature rise, the temperature is lowered from the melting temperature to a temperature lower than the softening point temperature, the melted sealing material for sealing is solidified, and the first and second substrates are sealed,
After exhausting the temperature, exhausting the space and then enclosing a discharge gas in the space;
A method for manufacturing a plasma display panel.   2. The plasma display panel according to claim 1, wherein the exhaust of the gas in the space during the second temperature rise is performed using an elastic force of at least one of the first and second substrates. Production method. During the second temperature rise,
Elastic deformation of the first and second substrates from the inelastic deformation position to the elastic deformation position is performed by introducing the dry gas into the space,
The elastic deformation of the first and second substrates from the elastic deformation position to the inelastic deformation position causes the gas in the space to flow by the elastic force of at least one of the first and second substrates. This is done by extruding and exhausting from the space.
The method for manufacturing a plasma display panel according to claim 1. The method of manufacturing a plasma display panel according to claim 1, wherein the dry gas includes any one of N ₂ , He, Ne, Ar, Xe, Kr, and O _2. .   The first and second substrates are not elastically deformed alternately between the inelastic deformation position and the elastic deformation position when the temperature is lowered from the melting temperature to the vicinity of the softening point temperature during the temperature lowering. 5. The method for producing a plasma display panel according to any one of 4 above.   The first temperature increase is performed by controlling the introduction of the dry gas into the space and the exhaust of the gas in the space, so that the first and second elastic deformation positions and the elastic deformation positions are controlled. The method for producing a plasma display panel according to claim 1, wherein the method is performed while alternately elastically deforming the substrate.   The method for manufacturing a plasma display panel according to claim 1, wherein the introduction of the dry gas is performed such that the flow rate gradually increases.

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