JP2012243607A - Plasma display panel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a plasma display panel with an excellent display characteristic that can reduce a sustained discharge voltage by improving an electron emission characteristic of a protective layer, and that can be driven at a low voltage at high luminance even in a high-definition image.SOLUTION: A plasma display panel manufacturing method has a sealing and exhausting step, in which an electrode, a dielectric body, a front plate, on which a protective layer is formed, and a back plate are opposed to each other with a discharge space formed, and sealed by a sealing material, and gas in the discharge space is exhausted. The sealing and exhausting step has a step of exhausting the gas in the discharge space during or after sealing the front plate and the back plate, a step of introducing gas containing reductive organic gas in the discharge space, a step of exhausting the reductive organic gas, and a step of sealing discharge gas in the discharge space. The gas containing the reductive organic gas contains a component of the discharge gas.

Description

  The technology disclosed herein relates to a method of manufacturing a plasma display panel used for a display device or the like.

  A plasma display panel (hereinafter referred to as PDP) includes a front plate and a back plate. The front plate includes a glass substrate, a display electrode formed on one main surface of the glass substrate, a dielectric layer that covers the display electrode and functions as a capacitor, and magnesium oxide formed on the dielectric layer It is comprised with the protective layer which consists of (MgO). On the other hand, the back plate includes a glass substrate, a data electrode formed on one main surface of the glass substrate, a base dielectric layer covering the data electrode, a partition formed on the base dielectric layer, and each partition It is comprised with the fluorescent substance layer which light-emits each in red, green, and blue formed in between.

  The protective layer mainly has two functions. The first is to protect the dielectric layer from ion bombardment due to discharge. The second is to release initial electrons for generating an address discharge. By protecting the dielectric layer from ion bombardment, an increase in discharge voltage is suppressed. By increasing the number of initial electron emissions, address discharge errors that cause image flickering are reduced. In order to increase the initial electron emission number, a technique for adding impurities to MgO and a technique for forming MgO particles on an MgO film are known (see, for example, Patent Document 1).

JP 2002-260535 A

  In recent years, high definition has been advanced in televisions, and a low-cost, low-power-consumption, high-brightness full HD (high definition) (1920 × 1080 pixels: progressive display) PDP is required in the market. Since the electron emission characteristics from the protective layer determine the image quality of the PDP, it is very important to control the electron emission characteristics.

  As described above, in order to advance the high definition and low power consumption of the PDP, it is necessary to simultaneously realize that the discharge voltage is not increased and that the image quality is improved by reducing defective lighting. There was a problem.

  The present invention has been made in view of such a problem, and an object of the present invention is to realize a PDP having high luminance display performance and capable of being driven at a low voltage.

  In order to solve the above-described problems, a method for manufacturing a PDP according to the present invention includes a front plate on which an electrode, a dielectric, and a protective layer are formed, and a back plate, which are arranged to face each other while forming a discharge space. In the method for manufacturing a plasma display panel having a sealing exhaust process, in which the gas in the discharge space is exhausted and sealed, the sealing exhaust process includes a period of sealing the front plate and the back plate, or After sealing, exhausting the gas in the discharge space; introducing a gas containing a reducing organic gas into the discharge space; exhausting the reducing organic gas; and discharging into the discharge space Sealing the gas, and the gas containing the reducing organic gas contains a component of the discharge gas.

  Here, the reducing organic gas is preferably at least one selected from acetylene, ethylene, methylacetylene, propadiene, propylene, cyclopropane, propane and butane.

  According to the present invention, it is possible to improve the electron emission characteristics in the protective layer, reduce the sustain discharge voltage, and realize a PDP excellent in display characteristics that can be driven with high brightness and low voltage even in high-definition images. Can do.

The perspective view which shows the structure of PDP which concerns on embodiment Flow chart of manufacturing method of PDP according to embodiment The figure which shows the 1st profile example The figure which shows the 2nd profile example The figure which shows the 3rd profile example The figure which shows the example of a 4th profile The figure which shows the example of a 4th profile The figure which shows the example of a 5th profile

[1. Structure of PDP1]
The basic structure of the PDP is a general AC surface discharge type PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other. The front plate 2 and the back plate 10 are hermetically sealed with a sealing material whose outer peripheral portion is made of glass frit or the like. A discharge gas such as neon (Ne) and xenon (Xe) is sealed at a pressure of 53 kPa to 80 kPa in the discharge space 16 inside the sealed PDP 1.

  On the front glass substrate 3, a pair of strip-like display electrodes 6 each composed of the scanning electrodes 4 and the sustain electrodes 5 and a plurality of black stripes 7 are arranged in parallel to each other. A dielectric layer 8 that functions as a capacitor is formed on the front glass substrate 3 so as to cover the display electrodes 6 and the black stripes 7. Further, a protective layer 9 made of magnesium oxide (MgO) or the like is formed on the surface of the dielectric layer 8. The protective layer 9 will be described later in detail.

Scan electrode 4 and sustain electrode 5 are each formed by laminating a bus electrode made of Ag on a transparent electrode made of a conductive metal oxide such as indium tin oxide (ITO), tin oxide (SnO ₂ ), and zinc oxide (ZnO). Has been.

  On the rear glass substrate 11, a plurality of data electrodes 12 made of a conductive material mainly composed of silver (Ag) are arranged in parallel to each other in a direction orthogonal to the display electrodes 6. The data electrode 12 is covered with a base dielectric layer 13. Further, a partition wall 14 having a predetermined height is formed on the underlying dielectric layer 13 between the data electrodes 12 to divide the discharge space 16. In the grooves between the barrier ribs 14, a phosphor layer 15 that emits red light by ultraviolet rays, a phosphor layer 15 that emits green light, and a phosphor layer 15 that emits blue light are sequentially applied and formed for each data electrode 12. Yes. A discharge cell is formed at a position where the display electrode 6 and the data electrode 12 intersect. Discharge cells having red, green, and blue phosphor layers 15 arranged in the direction of the display electrode 6 serve as pixels for color display.

  In the present embodiment, the discharge gas sealed in the discharge space 16 contains 10% by volume to 30% by volume of Xe.

[2. Manufacturing method of PDP1]
As shown in FIG. 2, the manufacturing method of PDP 1 according to the present embodiment includes a front plate manufacturing process A1, a back panel manufacturing process B1, a frit coating process B2, a sealing process C1, a reducing gas introduction process C2, and an exhaust process. C3 and discharge gas supply step C4.

[2-1. Front plate manufacturing process A1]
In front plate manufacturing step A1, scan electrodes 4, sustain electrodes 5, and black stripes 7 are formed on front glass substrate 3 by photolithography. Scan electrode 4 and sustain electrode 5 have metal bus electrodes containing silver (Ag) for ensuring conductivity. Scan electrode 4 and sustain electrode 5 have transparent electrodes. The metal bus electrode is laminated on the transparent electrode.

  As a material for the transparent electrode, indium tin oxide (ITO) or the like is used to ensure transparency and electric conductivity. First, an ITO thin film is formed on the front glass substrate 3 by sputtering or the like. Next, a transparent electrode having a predetermined pattern is formed by lithography.

  As a material for the metal bus electrode, an electrode paste containing silver (Ag), a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, an electrode paste is applied on the front glass substrate 3 by a screen printing method or the like. Next, the solvent in the electrode paste is removed by a drying furnace. Next, the electrode paste is exposed through a photomask having a predetermined pattern.

  Next, the electrode paste is developed to form a metal bus electrode pattern. Finally, the metal bus electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the metal bus electrode pattern is removed. Further, the glass frit in the metal bus electrode pattern is melted. The molten glass frit is vitrified after firing. A metal bus electrode is formed by the above process.

  The black stripe 7 is formed of a material containing a black pigment. Next, the dielectric layer 8 is formed. As a material for the dielectric layer 8, a dielectric paste containing a dielectric glass frit, a resin, a solvent, and the like is used. First, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrodes 4, the sustain electrodes 5 and the black stripes 7 with a predetermined thickness. Next, the solvent in the dielectric paste is removed by a drying furnace. Finally, the dielectric paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the dielectric paste is removed. Further, the dielectric glass frit is melted. The molten dielectric glass frit is vitrified after firing. Through the above steps, the dielectric layer 8 is formed. Here, besides the method of die coating the dielectric paste, a screen printing method, a spin coating method, or the like can be used.

The material of the dielectric layer 8 is at least one selected from bismuth oxide (Bi ₂ O ₃ ), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO), molybdenum oxide (MoO ₃ ), and oxidation. And at least one selected from tungsten (WO ₃ ), cerium oxide (CeO ₂ ), and manganese dioxide (MnO ₂ ). The binder component is ethyl cellulose, or terpineol containing 1% to 20% by weight of acrylic resin, or butyl carbitol acetate. In the paste, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, and tributyl phosphate are added as needed, and glycerol monooleate, sorbitan sesquioleate, and homogenol (Kao Corporation) as dispersants. The printing property may be improved as a paste by adding a phosphate ester of an alkyl allyl group, etc.

  The protective layer 9 is formed of a metal oxide made of at least two oxides selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). These metal oxides have a peak between the minimum diffraction angle and the maximum diffraction angle generated from a single oxide constituting the metal oxide having a specific orientation plane in the X-ray diffraction analysis of the protective layer 9.

In this embodiment, the protective layer 9 is formed by electron beam evaporation. As described above, the front glass substrate 3 on which the layers up to the dielectric layer 8 are formed is placed in a vacuum chamber. The ultimate vacuum is about 1.0 × 10 ⁻⁴ Pa, and the front glass substrate 3 is heated to about 180 ° C. to 320 ° C. The vapor deposition atmosphere flows into the vacuum chamber so as to be about 4.0 × 10 ⁻³ Pa.

  The vapor deposition material is formed of two or more metal oxides as described above. In this embodiment, metal oxides are mixed in powder form and processed into a tablet shape having a diameter of about 5 mm and a thickness of about 2 mm by high temperature and high pressure. Not limited to this, each metal oxide crystal may be pulverized to about 10 mm to 15 mm and mixed. Then, a cooled vessel (hearth) made of copper or carbon is placed in a vacuum chamber, and a vapor deposition material is put therein.

  A pierce-type electron gun is used as an electron gun for generating an electron beam, and the generated electron beam is guided to the hearth by a deflection coil or the like and irradiated onto the deposition material.

  The film forming rate of the protective layer 9 is monitored by a crystal resonator or the like, and is set to a film thickness of about 500 nm to 1000 nm. The front glass substrate 3 may be a fixed type or a transport type.

  Note that magnesium oxide crystal particles formed by vapor phase synthesis or the like may be attached to the protective layer 9 on the film.

  Through the above steps, the scanning electrode 4, the sustain electrode 5, the black stripe 7, the dielectric layer 8, and the protective layer 9 are formed on the front glass substrate 3, and the front plate 2 is completed.

[2-2. Back plate manufacturing process B1]
First, the data electrode 12 is formed on the rear glass substrate 11 by photolithography. As a material of the data electrode 12, a data electrode paste containing silver (Ag) for ensuring conductivity, a glass frit for binding silver, a photosensitive resin, a solvent, and the like is used. First, the data electrode paste is applied on the rear glass substrate 11 with a predetermined thickness by a screen printing method or the like. Next, the solvent in the data electrode paste is removed by a drying furnace. Next, the data electrode paste is exposed through a photomask having a predetermined pattern. Next, the data electrode paste is developed to form a data electrode pattern. Finally, the data electrode pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the data electrode pattern is removed. Further, the glass frit in the data electrode pattern is melted. The molten glass frit is vitrified after firing. The data electrode 12 is formed by the above process. Here, besides the method of screen printing the data electrode paste, a sputtering method, a vapor deposition method, or the like can be used.

  Next, the base dielectric layer 13 is formed. As a material for the base dielectric layer 13, a base dielectric paste containing a dielectric glass frit, a resin, a solvent, and the like is used. First, a base dielectric paste is applied by a screen printing method or the like so as to cover the data electrode 12 on the rear glass substrate 11 on which the data electrode 12 is formed with a predetermined thickness. Next, the solvent in the base dielectric paste is removed by a drying furnace. Finally, the base dielectric paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the base dielectric paste is removed. Further, the dielectric glass frit is melted. The molten dielectric glass frit is vitrified after firing. Through the above steps, the base dielectric layer 13 is formed. Here, other than the method of screen printing the base dielectric paste, a die coating method, a spin coating method, or the like can be used.

  Next, the partition wall 14 is formed by photolithography. As a material for the partition wall 14, a partition paste containing a filler, a glass frit for binding the filler, a photosensitive resin, a solvent, and the like is used. First, the barrier rib paste is applied on the underlying dielectric layer 13 with a predetermined thickness by a die coating method or the like. Next, the solvent in the partition wall paste is removed by a drying furnace. Next, the barrier rib paste is exposed through a photomask having a predetermined pattern. Next, the barrier rib paste is developed to form a barrier rib pattern. Finally, the partition pattern is fired at a predetermined temperature in a firing furnace. That is, the photosensitive resin in the partition pattern is removed. Further, the glass frit in the partition wall pattern is melted. The molten glass frit is vitrified after firing. The partition wall 14 is formed by the above process. Here, in addition to the photolithography method, a sandblast method or the like can be used.

  Next, the phosphor layer 15 is formed. As the material of the phosphor layer 15, a phosphor paste containing phosphor particles, a binder, a solvent, and the like is used. First, a phosphor paste is applied on the base dielectric layer 13 between adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14 by a dispensing method or the like. Next, the solvent in the phosphor paste is removed by a drying furnace. Finally, the phosphor paste is fired at a predetermined temperature in a firing furnace. That is, the resin in the phosphor paste is removed. The phosphor layer 15 is formed by the above steps. Here, in addition to the dispensing method, a screen printing method or the like can be used.

  Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

[2-3. Frit application process B2]
Next, the glass frit which is a sealing member is apply | coated outside the image display area | region of the backplate 10 produced by backplate preparation process B1. Thereafter, in order to remove the resin component and the like of the glass frit, a frit coating step B2 is performed in which temporary baking is performed at a temperature of about 350 ° C.

Here, the sealing member is preferably a frit mainly composed of bismuth oxide or vanadium oxide. Examples of the frit containing bismuth oxide as a main component include, for example, a Bi ₂ O ₃ —B ₂ O ₃ —RO—MO system (where R is any one of Ba, Sr, Ca, and Mg, and M is Any of Cu, Sb, and Fe)) and a filler made of an oxide such as Al ₂ O ₃ , SiO ₂ , and cordierite can be used. In addition, as a frit containing vanadium oxide as a main component, for example, a filler made of an oxide such as Al ₂ O ₃ , SiO ₂ , cordierite is added to a V ₂ O ₅ —BaO—TeO—WO glass material. Things can be used.

[2-4. From sealing process C1 to discharge gas supply process C4]
Next, the front plate 2 and the back plate 10 that has undergone the frit coating step B2 are arranged to face each other, and the peripheral portion is sealed with a sealing member. Thereafter, the gas in the discharge space is exhausted. Thereafter, a discharge gas is sealed in the discharge space. As described above, in the present embodiment, the period in which the front plate 2 and the back plate 10 are sealed, or the step of exhausting the gas in the discharge space after sealing, and the reducing organic gas is exposed to the discharge space. And a step of exhausting the reducing organic gas. That is, the following steps are performed.

  The sealing process C1, the reducing gas introduction process C2, the exhaust process C3, and the discharge gas supply process C4 according to the present embodiment perform the processing of the temperature / pressure profile shown in FIGS. Each figure (a) shows a temperature profile, and each figure (b) shows a pressure profile in PDP1. In the present embodiment, the primary exhaust process E1 for exhausting the gas in the discharge space of the PDP 1 is performed after the sealing process C1 is completed or during the process.

  The sealing temperature in the figure is a temperature at which the front plate 2 and the back plate 10 are sealed by a frit that is a sealing member. The sealing temperature in the present embodiment is about 490 ° C., for example. Further, the exhaust temperature in the figure is the temperature at which the gas in the PDP 1 is exhausted in order to put the discharge gas into the PDP 1. The exhaust temperature in the present embodiment is about 400 ° C., for example.

[2-4-1. First profile example]
FIG. 3 shows a first profile example in the present embodiment. As shown in the figure, first, the temperature rises from room temperature to the sealing temperature. The temperature is then maintained at the sealing temperature during period ab. Next, from time b, the temperature falls from the sealing temperature to the exhaust temperature. This is the sealing step C1.

  The exhaust temperature is maintained for a period up to time e. Then, the temperature is lowered until the period of time f.

  In the sealing, as the temperature rises in the sealing step C1, the sealing member described above is softened, the front plate 2 and the rear plate 10 are bonded together by the sealing member, the inside of the PDP 1 is hermetically sealed, It is considered that the process is completed in a state where no gas passes through. As a result of studies by the inventors, this is completed at about T + 150 ° C. with respect to the transition point T ° C. of the sealing member. In the present embodiment, the above-described sealing member is used, and this temperature is in the range of 450 ° C to 500 ° C.

  In the present embodiment, the primary exhaust process E1 is performed from the temperature at which the sealing is completed. This discharges the inside of the discharge space 16 from the exhaust pipe provided on the back plate 10 to make a vacuum state. Thereby, in the reducing gas introduction process C2 performed later, the reducing organic gas is evenly distributed throughout the PDP 1 and the effect of the reducing gas on the protective layer 9 becomes uniform in the surface of the PDP 1.

  In the present embodiment, the protective layer 9 is not a single component of magnesium oxide, but includes a plurality of components of magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). It is a protective layer. Such a protective layer is easily deteriorated by the influence of the surrounding atmosphere, and hydroxylation and carbonation easily occur. In particular, when carbonation occurs, there arises a problem that the discharge starting voltage becomes high as PDP1. Therefore, the carbonation of the protective layer 9 can be prevented by performing the primary exhaust process E1 before the reducing gas introduction process C2 as in the present embodiment.

Although it is desirable that the processing time of the primary exhaust process E1 is long, it is necessary to consider production efficiency. Therefore, it is desirable to maintain the minimum vacuum for 10 min to 20 min in a state where the ultimate vacuum is 1.0 × 10 ⁻⁴ Pa. . The ultimate vacuum is a numerical value measured on the exhaust device side, and the ultimate vacuum in the PDP 1 is one digit or more higher than the numerical value.

  After the primary exhaust process E1 is completed, a reducing gas introduction process C2 is performed. In this step, the temperature is maintained at the exhaust temperature for a period of cd. Then, a gas containing a reducing organic gas is introduced into the discharge space during the period cd. The protective layer 9 is exposed to a gas containing a reducing organic gas during the period cd. Also in the reducing gas introduction step C2, the exposure time to the reducing organic gas is preferably longer, but in consideration of production efficiency, it is set to about 20 min to 60 min. Further, as a result of investigations by the inventors, it has been found that the higher the ultimate pressure of the reducing organic gas in the PDP 1 during this period, the higher the effect. This is considered to be due to the fact that the absolute amount of the reducing organic gas in contact with the protective layer 9 is large and the absolute amount of the reaction of the protective layer 9 increases. Similarly, even if the concentration of the reducing organic gas is high, the effect becomes higher.

  In the present embodiment, the gas to be introduced contains 1.5% to 6.5% of a reducing organic gas (gas species will be described later), and Ne or the like as a gas (base gas) other than the reducing organic gas The overall pressure is about 80 kPa to atmospheric pressure. Here, Ne is taken as an example of the base gas, but it is desirable to use one component of the discharge gas that encloses the base gas in the PDP 1. As a result, even if the introduced gas remains in the discharge space, the discharge characteristics of the PDP can be prevented from being affected.

  Thereafter, in the exhaust process C3 (indicated by E2 in FIG. 3B), the temperature is maintained at the exhaust temperature for a predetermined period. Thereafter, the temperature drops to about room temperature. In the period d-e, the gas containing the reducing organic gas is discharged by exhausting the inside of the discharge space.

  Next, in the discharge gas supply process C4, a discharge gas is introduced into the discharge space. That is, the discharge gas is introduced in a period after e when the temperature drops to about room temperature.

  In the present embodiment, the primary exhaust period E1 is started before the period ab. However, the present invention is not limited to this, and it may be started in the middle of the temperature holding period ab.

  In the present embodiment, the reducing gas introduction step C2 is started immediately after the temperature is lowered to the exhaust temperature. However, the present invention is not limited to this, and may be started in the middle of the exhaust temperature holding period de.

[2-4-2. Second profile example]
A second profile example is as shown in FIG. The second profile example is different from the first profile example in that the reducing gas introduction step C2 (period cd) is performed in the sealing temperature holding period ad.

  Thereby, since the reducing gas introduction process C2 is performed at a higher temperature, the effect of reducing the discharge voltage by the reducing organic gas is further increased. The exhaust process C3 is performed after the reducing gas introduction process C2. Other steps are the same as those in the first profile example.

[2-4-3. Third profile example]
A third profile example is shown in FIG. The third profile example is different from the first profile example at the start of the primary exhaust process E1.

  In the first profile example, the primary exhaust process E1 is started when the sealing of the front plate 2 and the back plate 10 is completed. On the other hand, in the third profile example, the primary exhaust stroke E1 is started before the sealing of both is completed.

  In the first profile example, the primary exhaust process E1 is started when the temperature of the PDP 1 is 450 ° C. to 490 ° C., but the carbonation of the protective layer 9 is started at this temperature although it is a small amount. Therefore, in the third profile example, the primary exhaust stroke E1 is started from a temperature at which no carbonation of the protective layer 9 occurs. In this embodiment, the operation is started at 150 ° C. to 400 ° C. As a result, the effect of suppressing the carbonation of the protective layer 9 is further increased.

  As described above, in the third profile example, since the sealing between the front plate 2 and the back plate 10 is not completed, the gas outside the PDP 1 is exhausted at the start of the primary exhaust stroke E1. By making the ultimate vacuum in the primary exhaust stroke E1 equal to that in the first profile example, it is possible to obtain an effect of making the PDP1 plane uniform.

[2-4-4. Fourth profile example]
A fourth profile example is shown in FIG. The fourth profile example is different from the first profile example in the pressure of the reducing gas introduction process C2 for introducing the reducing organic gas. In the fourth profile example, the pressure in the reducing gas introduction step C2 is set to atmospheric pressure or higher.

  Thereby, in the reducing gas introduction process C2, the reducing gas can surely reach the in-plane central portion of the PDP 1. As a result, the reducing gas can be uniformly exposed throughout the protective layer 9 of the PDP 1, and the effect of reducing the discharge voltage becomes more uniform.

  In the present embodiment, the pressure in the reducing gas introduction step C2 is set to 110 kPa to 120 kPa.

  In the fourth profile example, the pressure of the reducing gas in the PDP 1 is set to be equal to or higher than the atmospheric pressure in the entire period of the reducing gas introduction process C2, but not limited thereto, as shown in FIG. 7, the pressure in the PDP 1 It may be instantaneously over atmospheric pressure. Thereafter, the pressure in the PDP 1 becomes about atmospheric pressure by the recovery of the shapes of the front plate 2 and the back plate 10. In this method, the same effect as that of the fourth profile example can be obtained, and further, the risk of destroying the PDP 1 can be reduced by setting the interior to atmospheric pressure or higher.

[2-4-5. Fifth profile example]
A fifth profile example is as shown in FIG. The fifth profile example is different from the first profile example in the temperature at which reducing gas is introduced in the reducing gas introduction step C2.

  In general, when gas is introduced into a PDP with a front plate and a rear plate sealed, it is necessary to introduce gas from an exhaust pipe or the like, so that the protective layer and phosphor layer in all regions in the PDP are exposed to the gas at the same time. Instead, the gas is sequentially exposed from the area close to the exhaust pipe.

  For this reason, even when introducing the reducing gas into the PDP 1, if the reducing gas is at or above the temperature at which it reacts with the protective layer, the reaction is started sequentially from the region where the reducing gas is in contact with the protective layer. . As a result, unevenness depending on the degree of reaction between the protective layer and the reducing gas occurs in the PDP surface, and similarly, the degree of the effect of reducing the discharge voltage in the PDP surface also varies.

  Therefore, in the fifth profile example, the temperature of the PDP 1 when the reducing gas is introduced in the reducing gas introduction step C2 is set lower than the temperature at which the reducing gas and the protective layer start reaction. As shown in the figure, the temperature when the reducing gas is introduced is T1. As a result, the reducing gas does not react with the protective layer from the exposed area in the PDP 1, and the reducing gas spreads throughout the PDP 1. Further, by lowering the temperature in this way, the degree of vacuum in the PDP 1 before the introduction of the reducing gas is further improved. That is, the degree of vacuum P2 (Pa) in the PDP 1 before introducing the reducing gas in this example profile is P2 in the PDP 1 before introducing the reducing gas in the first profile example described above. <P1.

  And after hold | maintaining the time (about 10 minutes with 42-inch size PDP) that reducing gas spreads throughout the inside of PDP1, the temperature of PDP1 is raised again more than the temperature which a reducing gas and a protective layer react. As a result, the reducing gas and the protective layer start reacting almost simultaneously in the plane of the PDP 1, and the reaction progresses uniformly. Similarly, the effect of uniformly reducing the discharge voltage in the PDP plane is obtained.

  Here, in the fifth profile example, the temperature T1 is set as the temperature at which the reaction between the reducing gas and the protective layer does not start, but this differs depending on the reducing gas type used. In the gas used in the examination of the reducing organic gas species described later, the reaction between the reducing gas and the protective layer can be prevented by setting the temperature of the PDP 1 to 300 ° C. or lower.

  Further, in the fifth profile example, an effect of preventing the reaction between the reducing gas and the protective layer can be obtained by lowering the temperature T1, but on the other hand, an adverse effect is also caused by making the temperature T1 too low. There was found. When the temperature T1 is low, the reducing gas is adsorbed on the phosphor layer or the partition wall having a large surface area, and there may be a region where the reaction between the reducing gas and the protective layer does not occur even if the temperature is raised later. It became clear. As a result of experiments by the inventors, in the reducing organic gas species described later, adsorption of the reducing gas to the phosphor layer can be prevented by setting the lower limit value of the temperature T1 to 50 ° C. to 100 ° C. .

  From these results, in the fifth profile example, the temperature T1 of the PDP 1 is set to 300 ° C. or lower and 100 ° C. or higher when the gas in the reducing gas introduction step C2 is introduced. As a result, the reaction between the reducing gas and the protective layer can be performed uniformly in the PDP plane, and the effect of suppressing the unevenness in the PDP1 plane of the discharge voltage can be obtained.

[2-4-6. Details of reducing organic gas]
As shown in Table 1, the reducing organic gas is preferably a CH-based organic gas having a molecular weight of 58 or less and a large reducing power. When at least one selected from various reducing organic gases is mixed with a rare gas or nitrogen gas, a gas containing the reducing organic gas is produced.

  In Table 1, column C means the number of carbon atoms contained in one molecule of organic gas. The column of H means the number of hydrogen atoms contained in one molecule of the organic gas.

  As shown in Table 1, “A” is given to a gas having a vapor pressure of 100 kPa or higher at 0 ° C. in the vapor pressure column. Furthermore, “C” is given to the gas whose vapor pressure at 0 ° C. is smaller than 100 kPa. In the boiling point column, a gas having a boiling point of 0 ° C. or less at 1 atm is marked with “A”. Furthermore, “C” is attached to a gas having a boiling point of greater than 0 ° C. at 1 atmosphere. In the column for easy decomposition, “A” is given to the gas that is easily decomposed. “B” is attached to a gas that is easily decomposed. In the column of reducing power, “A” is given to the gas having sufficient reducing power.

  In Table 1, “A” means good characteristics. “B” means normal characteristics. “C” means insufficient properties.

  From the viewpoint of easy handling of organic gas in the manufacturing process of PDP, a reducing organic gas that can be supplied in a gas cylinder is desirable. Also, considering the ease of handling in the manufacturing process of PDP, a reducing organic gas having a vapor pressure at 100 ° C. of 100 kPa or higher, a reducing organic gas having a boiling point of 0 ° C. or lower, or a reducing organic gas having a low molecular weight is present. desirable.

  Furthermore, part of the gas containing the reducing organic gas may remain in the discharge space even after the exhaust process C3. Therefore, it is desirable that the reducing organic gas has a characteristic that it is easily decomposed.

  Reducing organic gas is a carbon that does not contain oxygen selected from acetylene, ethylene, methylacetylene, propadiene, propylene and cyclopropane, taking into consideration the ease of handling in the manufacturing process and the property of being easily decomposed. Hydrogen gas is desirable. At least one selected from these reducing organic gases may be mixed with a rare gas or nitrogen gas.

As a result of experiments conducted by the present inventors, for example, when propylene gas or cyclopropane gas having a chemical formula of C ₃ H ₆ was used, the sustain voltage could be reduced by about 10V. Further, it was found that when the acetylene gas having a chemical formula of C ₂ H ₂ is used, the sustain voltage can be reduced by about 20V.

  The lower limit of the mixing ratio of the rare gas or nitrogen gas and the reducing organic gas is determined according to the combustion ratio of the reducing organic gas to be used. The upper limit is about several volume%. If the mixing ratio of the reducing organic gas is too high, the organic component is likely to be polymerized to become a polymer. In this case, the polymer remains in the discharge space and affects the characteristics of the PDP. Therefore, it is preferable to appropriately adjust the mixing ratio according to the component of the reducing organic gas to be used.

[3. Summary]
The method for manufacturing PDP 1 disclosed in the present embodiment includes the following steps. The protective layer 9 is exposed to the reducing organic gas by introducing a gas containing the reducing organic gas into the discharge space. Next, reducing organic gas is discharged from the discharge space. Next, the discharge gas is sealed in the discharge space.

  In the protective layer 9 exposed to the reducing organic gas, oxygen deficiency occurs. Oxygen deficiency is considered to improve the secondary electron emission ability of the protective layer. Therefore, PDP 1 manufactured by the manufacturing method according to the present embodiment can reduce the sustain voltage.

  Furthermore, the reducing organic gas is preferably a hydrocarbon-based gas that does not contain oxygen. This is because the reduction ability is enhanced by not containing oxygen.

  Further, the reducing organic gas is preferably at least one selected from acetylene, ethylene, methylacetylene, propadiene, propylene, cyclopropane, propane and butane. This is because the reducing organic gas is easy to handle in the manufacturing process. Furthermore, it is because said reducing organic gas is easy to decompose | disassemble.

  In the present embodiment, a manufacturing method in which a gas containing a reducing organic gas is introduced into the discharge space after the discharge space is exhausted is exemplified. However, the gas containing the reducing organic gas can be introduced into the discharge space by continuously supplying the gas containing the reducing organic gas to the discharge space without exhausting the discharge space.

In the above description, an MgO film is taken as an example of the base layer. However, the performance required for the underlayer is to have high spatter resistance for protecting the dielectric from ion bombardment. That is, the charge holding ability and the electron emission performance need not be high. In conventional PDPs, a protective layer composed mainly of MgO is very often formed in order to achieve both the electron emission performance above a certain level and the sputter resistance. However, when the electron emission performance is controlled predominantly by the metal oxide crystal particles, the underlying layer does not need to be MgO at all. For the underlayer, other materials having excellent impact resistance such as Al ₂ O ₃ may be used.

  Moreover, in this Embodiment, MgO was illustrated as a metal oxide crystal particle. However, even with other single crystal particles, similar effects can be obtained by using crystal particles made of metal oxides such as Sr, Ca, Ba, Al, etc., which have high electron emission performance like MgO. Thus, the metal oxide crystal particles are not limited to MgO.

  As described above, the technique disclosed in the present embodiment is useful for realizing a PDP having high image quality display performance and low power consumption.

1 PDP
DESCRIPTION OF SYMBOLS 2 Front plate 3 Front glass substrate 4 Scan electrode 5 Sustain electrode 6 Display electrode 7 Black stripe 8 Dielectric layer 9 Protective layer 10 Back plate 11 Back glass substrate 12 Data electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space

Claims (2)

A front plate on which an electrode, a dielectric, and a protective layer are formed, and a back plate are disposed opposite to each other so as to form a discharge space, sealed with a sealing material, and exhausted in the discharge space. In the method of manufacturing a plasma display panel having an exhaust process,
In the sealing exhaust process,
Exhausting the gas in the discharge space after sealing the front plate and the back plate, or after sealing;
Introducing a gas containing a reducing organic gas into the discharge space;
Exhausting the reducing organic gas;
Enclosing a discharge gas in the discharge space;
Have
The gas containing the reducing organic gas contains a component of the discharge gas,
A method for manufacturing a plasma display panel. The reducing organic gas is at least one selected from acetylene, ethylene, methylacetylene, propadiene, propylene, cyclopropane, propane and butane.
The method for manufacturing a plasma display panel according to claim 1.

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