JP4556751B2 - Plasma display panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a gas discharge display device, and more particularly to a plasma display panel known as a display device for displaying images and images by exciting phosphors of red, green, and blue colors with ultraviolet rays by rare gas discharge and a method for manufacturing the same It is about.

  In recent years, expectations for large-screen thin television receivers and public display devices as interactive information terminals have increased, and there are many liquid crystal display panels (LCD), field emission displays (FED), electroluminescence (EL) displays, etc. Display devices have been proposed. Among these display devices, a plasma display panel (hereinafter also abbreviated as PDP) is a self-luminous type capable of displaying beautiful images and is easy to make large screens. It is attracting attention and development is progressing toward higher definition and larger screen.

  This PDP can be broadly divided into AC and DC types, and there are two types of discharge types: surface discharge type and counter discharge type. Compared to high resolution and large screen efforts. At present, AC-type and surface-discharge type PDPs have become the mainstream because of their easy progress and ease of manufacturing.

  An AC type surface discharge type PDP has a configuration in which a transparent substrate includes a plurality of parallel stripe-shaped sustain electrodes and display electrodes including scan electrodes, a dielectric layer, and a protective film (also referred to as a protective layer) made of MgO. A display plate and a front plate on which an object is formed, and a back plate on which a plurality of striped address electrodes (also referred to as data electrodes), a base dielectric layer, a partition wall, a phosphor layer, and the like are formed on another substrate And the data electrodes are orthogonal to each other and arranged to form a minute space (internal space) inside, and the periphery is sealed with a sealing member, and neon and xenon are mixed in the internal space. The discharge gas to be formed is sealed at a pressure of about 66500 Pa (about 500 Torr), for example (see Non-Patent Document 1, for example).

  And in order to achieve higher efficiency and higher image quality of PDP, higher efficiency is achieved by various methods, including further increase of Xe to increase the Xe gas pressure, which is an ultraviolet ray source generated by discharge. It is being considered to plan. However, problems such as variations in the discharge itself due to high efficiency, a decrease in the operation life of the PDP, and an increase in sputtering of the protective film and an unstable operation of the PDP become more prominent than before. There is a trend. Such variations in discharge, reduction in life, malfunction due to sputtering of the protective film, etc. are considered to be due to the influence of impurity gas (for example, CH gas) mixed in the discharge gas inside the panel of the PDP. Countermeasures against these impurity gases have not been easy. Accordingly, various methods have been proposed to prevent the impurity gas from being mixed into the discharge gas inside the P panel of the PD (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).

  Here are some examples of these methods. As described above, the PDP has a front plate in which a display electrode, a dielectric layer, and a protective film are formed on a front glass substrate, an address electrode, a base dielectric layer, a barrier rib, and a phosphor layer on the rear glass substrate. Is formed so as to face each other with a discharge space in between, and a material forming each component of the PDP often includes a CH-based material. These materials remove CH residue by baking in the process or washing after formation, but they may not be completely removed and may remain. All of the proposed methods add additional cleaning after the step of forming each component, or perform additional processing.

For example, when barrier ribs or electrodes are formed by photolithography, a photoresist agent is used. Therefore, residual resist at the time of barrier rib or electrode formation may cause impurity gas in the panel, and resist residue between the electrodes If there is, it will cause the generation of impurities and bubbles in the dielectric, so the resist removability is improved by washing with ozone water or ion water before embedding the partition material or before firing the electrode, There is a method for improving the insulation between electrodes and suppressing the generation of impurity gas by eliminating the residue of a resist made of a CH-based compound in the PDP panel. In addition, after forming the transparent electrode on the substrate when forming the front plate of the PDP, and after receiving the substrate when forming the back plate of the PDP or after forming the address electrode on the substrate, etc. There is a method for preventing generation of impurity gas including CH system without cleaning or treating reaction of organic substances attached on a substrate using a solution containing ozone in a sealed atmosphere, without leaving organic substances which are CH compounds. is there. Furthermore, before forming the dielectric layer in the PDP front plate forming process, and before forming the barrier ribs and before forming the phosphor layer when the substrate is received in the PDP back plate forming process. In each process, the organic substances that adhere or remain are effectively removed with a solution containing ozone or a solution containing ethylene carbonate, so that the organic substance that is a CH-based compound does not remain, and the impurity gas (CH-based) There is also a method of trying to suppress the generation of gas.
Heki Uchiike and Shigeo Miko, “All about Plasma Displays”, Industrial Research Council, Inc., May 1, 1997, p79-p80 JP 2002-75174 A JP 2004-6174 A Japanese Patent Laid-Open No. 2004-6177 Japanese Patent Laid-Open No. 2004-6180

  However, all of the above-described conventional methods add additional cleaning after the step of forming each component or additionally perform special treatment, so that there is very little CH-based residue. However, it is impossible to completely remove CH impurities such as an extremely small amount of organic substances. In particular, each component of the PDP having a dense and flat surface has a relatively high impurity removal rate, but those having a porous property are removed because the CH-based impurities penetrate into the component material. Becomes extremely difficult. In addition, since components such as MgO protective film and phosphor layer may be changed by washing and processing, the removal of CH-based impurities as shown in the above example It could not be processed by the method and was left as an issue.

  Further, it is considered from the viewpoint of removing the impurity gas present in the panel of the PDP, which is a cause of problems such as variations in discharge, a decrease in life, spattering of the protective film, and the like, and suppressing the influence of the impurity gas. In addition, the impurity gas cannot be sufficiently removed at a relatively low exhaust temperature in the exhaust / gas filling process when manufacturing an actual PDP, and the barrier ribs and phosphors that are the components of the panel before the exhaust process In addition, there is a problem that it is very difficult to remove the adsorbed gas including CH-based impurity gas that is physically adsorbed or chemically adsorbed on MgO, dielectric, etc., and it has been a challenge to develop a new method .

  The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a high-efficiency and high-quality PDP by suppressing the influence of CH-based impurity gas remaining inside the PDP panel.

In order to achieve the above object, the plasma display panel of the present invention is formed so that a plurality of display electrodes are formed and a front plate in which the display electrodes are covered with a dielectric layer and a protective film, and a discharge space is formed. An address electrode disposed opposite to the front plate and formed in a direction orthogonal to the display electrode, and a back plate having a phosphor layer formed between partition walls defining the discharge space, and discharging into the discharge space. A plasma display panel filled with gas has a configuration in which ozone is contained in the discharge gas in a range of 0.01 ppm to 5%.

  With these configurations, a PDP from which the CH-based impurity gas remaining in the panel is removed is obtained, so that there is no variation in discharge, a decrease in life, spattering of the protective film, etc. It is possible to provide a high-efficiency, high-quality PDP with less influence on the life characteristics.

In order to achieve the above object, a method of manufacturing a plasma display panel according to the present invention includes a front plate in which a plurality of display electrodes are formed and the display electrodes are covered with a dielectric layer and a protective film, and a discharge space. A back plate having a phosphor layer formed between the barrier ribs that form the address electrodes that are arranged to face the front plate and are formed in a direction orthogonal to the display electrodes to form the discharge space; In the manufacturing method of the plasma display panel in which the discharge space is filled with a discharge gas, a sealing step of sealing a panel composed of the front plate and the back plate arranged opposite to each other with a sealing member formed in a peripheral portion; An exhaust process for exhausting the gas inside the sealed panel, and in the sealing process or the exhaust process, whether the components inside the panel are in ozone or oxygen gas. It performs a process of exposing the gas containing at least one kind selected, and ozone in the discharge gas has a configuration that includes a range of 5% 0.01 ppm.

  By the manufacturing method having these processes and procedures, it cannot be sufficiently removed at a relatively low exhaust temperature in the conventional exhaust and gas filling process, and the partition walls which are each component of the panel until the exhaust process, It is possible to solve the problem that it was very difficult to remove impurity gas including CH, which is physically adsorbed or chemically adsorbed on phosphor, MgO, dielectric, etc., and CH impurity gas remaining inside the panel is removed. As a result, it is possible to achieve a highly efficient and high quality PDP by suppressing the influence of the impurity gas on the display quality without causing variations in discharge, a reduction in service life, and sputtering of the protective film. It becomes possible.

  According to the PDP of the present invention, it is possible to suppress the influence on the display quality and life characteristics such as the discharge variation due to the impurity gas and the sputtering of the protective film, thereby realizing a high quality and long life PDP. it can.

  Hereinafter, the PDP of the present invention will be described with reference to the drawings.

(Embodiment)
Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view showing a schematic configuration of a PDP in an embodiment of the present invention, and FIG. 2 is a plan view showing a schematic configuration of an image display unit of the PDP in an embodiment of the present invention. In FIG. 1 and FIG. 2, the same components are denoted by the same reference numerals.

  In FIG. 1, the PDP 100 includes a front plate 1 and a back plate 2. The front plate 1 is a stripe-shaped pair of a scanning electrode 4 and a sustaining electrode 5 as a component of the PDP 100 on a transparent front side substrate 3 such as a glass substrate made of sodium borosilicate glass or the like by a float method. A display electrode 6 is provided. Moreover, it may have a black stripe (not shown) for the purpose of improving contrast. A dielectric layer 7 covering the group of display electrodes 6 and a protective film 8 made of MgO are further provided on the dielectric layer 7. Scan electrode 4 and sustain electrode 5 are each composed of transparent electrodes 4a and 5a and bus electrodes 4b and 5b made of Cr / Cu / Cr or Ag or the like electrically connected to transparent electrodes 4a and 5a. Has been.

  The back plate 2 has an address electrode (also referred to as a data electrode) 10 formed as a component of the PDP 100 in a direction orthogonal to the display electrode 6 on the back side substrate 9 opposed to the substrate 3, and A color display is provided on the base dielectric layer 11 which is a base layer covering the address electrode 10, for example, stripe-shaped barrier ribs 12 on the base dielectric layer 11, side surfaces between the barrier ribs 12 and the surface of the base dielectric layer 11. For this purpose, it usually has a phosphor layer 13 in which three colors of red, green, and blue are sequentially arranged.

  The front plate 1 and the back plate 2 having the above-described configuration are arranged opposite to each other with the partition wall 12 interposed therebetween so that the display electrode 6 and the address electrode 10 are orthogonal to each other and form a minute internal space therein, and the periphery is sealed. After the PDP is assembled by sealing with a member, the gas in the panel is exhausted.

  As described above, since each component of the PDP is generally formed of a material containing a CH-based material, firing and cleaning are performed so as not to remain as CH-based impurities. In order to further reduce the residual impurities, the PDP in the embodiment of the present invention is manufactured by performing any one of the following three kinds of methods. The first method is a method of exhausting the gas inside the panel after sealing the panel while flowing a gas containing ozone. The second method is a method of sealing a panel by a conventional method, then introducing and holding a gas containing ozone in the sealed panel, and then exhausting the gas inside the panel. The third method is to seal the panel by a conventional method and then enter an exhaust process, and add a process of introducing a gas containing ozone into the panel during the exhaust process. Is exposed to ozone-containing gas, and finally the gas inside the panel is exhausted. In any of the above three methods, the effect of greatly reducing the amount of CH-based impurities remaining in the constituent elements of the PDP is recognized.

Subsequently, a discharge gas prepared by mixing a rare gas such as Ne (neon) or Xe (xenon) into the panel internal space of the PDP sealed and exhausted as described above, for example, has a pressure of about 66500 Pa (500 Torr). The PDP100 panel is completed by encapsulating. As already described, the PDP according to the embodiment of the present invention performs a process of exposing the components inside the panel with a gas containing ozone when sealing and exhausting, and therefore remains in the components in the panel. The amount of CH-based impurities is very low. However, since it is impossible to completely remove the ozone, the discharge gas is mixed with a small amount of ozone to suppress the influence of the CH-based impurity gas remaining in the panel due to the ozone. More specifically, a mixed gas prepared by mixing ozone at a predetermined pressure with at least one kind of gas constituting the discharge gas is prepared, and a discharge gas containing a small amount of ozone is formed in the PDP panel using the mixed gas. Introduced (enclosed). That is, in the PDP according to the embodiment of the present invention, the discharge gas is a mixed gas of ozone and at least one kind of rare gas. As will be described later, the discharge gas may contain at least one kind of rare gas and ozone and oxygen gas (O ₂ ), or the discharge gas may contain at least one kind of rare gas and oxygen gas (O ₂ ). May be included. The rare gas used for the discharge gas is at least one selected from He, Ne, Ar, Kr, and Xe, and is preferably a mixed gas of Ne and Xe.

  In FIG. 1, the front plate 1 and the back plate 2 are drawn apart from each other so that the internal configuration can be easily understood. However, in practice, the front plate 1 and the back plate 2 form a partition wall 12. In a state of being sandwiched, the partition 12 of the back plate 2 is disposed so as to be in contact with the front plate 1.

  A discharge is generated by a periodic voltage applied to the address electrode 10 and the display electrode 6 of the PDP 100 formed as described above, and the phosphor layer 13 is irradiated with ultraviolet rays emitted by the discharge to excite the phosphor. The image is displayed by converting it into visible light.

  On the other hand, in FIG. 2, the scan electrodes 4 and the sustain electrodes 5 are alternately arranged in the column direction so as to be adjacent to each other with the discharge gap 14 at the position indicated by A in each line of the matrix display. Yes. Here, the inner space of the PDP is partitioned by the barrier ribs 12, and a portion where the display electrode 6 and the address electrode 10 (not shown) are orthogonal functions as a discharge cell 15 which is a unit light emitting region. Further, a black stripe (not shown) may be formed in the non-light emitting region 16 for the purpose of improving contrast. Furthermore, although not visible in FIG. 2, it has a dielectric, a protective film made of MgO, and a phosphor.

  Here, the process of using ozone in the method for manufacturing the PDP in the embodiment of the present invention will be described once more. In the method of manufacturing a PDP in the embodiment of the present invention, a pair of front-side and back-side substrates arranged so as to face each other so as to form a discharge space partitioned by barrier ribs between the substrates is formed in each peripheral portion. It has a sealing step of sealing with a receiving member, an exhausting step of exhausting gas in both substrates, and a step of introducing (sealing) discharge gas.

  As already described in the problem to be solved by the invention, it is known that the presence of impurity gas in the panel of PDP may cause variation in discharge, reduction in life, sputtering of the protective film, and the like. However, the impurity gas could not be sufficiently removed at a relatively low exhaust temperature when manufacturing an actual PDP, and the barrier ribs, phosphors, MgO, which are the constituent elements of the panel, until the exhaust process. In addition, it is very difficult to remove the gas physically adsorbed or chemically adsorbed on the dielectric. On the other hand, although these physically adsorbed or chemically adsorbed impurity gases cannot be removed at the processing temperature in the PDP exhaust process, it is considered that the impurity gas is released into the panel from the components of the PDP by the energy due to discharge. During the operation, the CH-type gas released may adversely affect the panel characteristics. From this point of view, it is important to sufficiently remove the impurity gas in the exhaust process, and to reduce the impurity gas adsorbed on each component or convert it to a gas with little adverse effect.

  For this reason, in the method of manufacturing a PDP according to the embodiment of the present invention, the process of exposing the components inside the panel with a gas containing ozone in the sealing and exhausting process is performed, and CH remaining in the components in the panel The amount of system impurities is reduced, and a slight amount of ozone is mixed with the discharge gas to suppress the influence of the CH system impurity gas slightly remaining in the panel due to the ozone.

Here, ozone (O ₃ ) is composed of three oxygen atoms (O), and one of them has the property of giving one oxygen atom to other surrounding substances to return to oxygen molecules (O ₂ ). is there. This indicates that ozone has a strong oxidizing action. For this reason, it is well known that most organic substances and metals are oxidized by ozone. For example, a reaction in which CH gas is finally decomposed and oxidized into carbon dioxide and water by ozone is known. In addition, it is well known that all metals except the platinum group are oxidized by ozone. Therefore, by mixing ozone with the gas constituting the discharge gas, the impurity gas composed of the CH-based gas remaining in the PDP panel can be decomposed and removed.

  In addition, high Xe pressure is known as one of the techniques for achieving high efficiency in PDP, but if this high Xe pressure is increased, the sputtering rate of MgO in the protective film may increase, It is also known that the impurity gas affects the sputtering of MgO. That is, as one of the mechanisms of MgO sputtering, it is estimated that MgO is decomposed into Mg and O by electric discharge, but oxygen ions from the decomposed oxygen (O) react with Mg again and return to MgO. Based on this estimation, it is known that MgO is excellent in sputtering resistance in an atmosphere containing ozone. According to the viewpoint of this theory, by mixing a small amount of ozone into the discharge gas, Mg decomposed and formed by sputtering MgO of the protective film by discharge is rapidly oxidized by ozone and returned to MgO. It is thought that sputtering can be suppressed.

On the other hand, in the method for manufacturing a PDP in the embodiment of the present invention, a trace amount of ozone, oxygen gas, or both ozone and oxygen gas is mixed in the discharge gas. This is based on the reason described below. That is, as described above, ozone (O ₃ ) has a property of returning to oxygen molecules (O ₂ ) at room temperature. Therefore, it is considered that most ozone returns to oxygen molecules when the panel is left for a long period of time. In addition, ozone is known to be formed from oxygen (molecules) due to the presence of ultraviolet rays having a wavelength shorter than 220 nm. Therefore, there is a possibility that the oxygen gas changed from ozone enclosed in a small amount in the PDP panel will generate ozone again due to the ultraviolet rays generated from Xe by the discharge during the operation of the PDP. This is because the presence of ozone and oxygen gas is considered to change from time to time.

  In the discharge gas sealing step in the PDP manufacturing method of the present invention, as described above, it is manufactured by performing a step of introducing a discharge gas in which ozone is mixed with at least one kind of rare gas. Actually, for introducing the discharge gas, a mixed gas in which ozone is mixed with at least one kind of rare gas at a predetermined pressure may be prepared in advance and introduced into the panel of the PDP as a discharge gas. Only ozone may be introduced into the PDP panel together with a discharge gas composed of at least one kind of rare gas using a separate pipe, and ozone may be introduced into the PDP panel in different forms. However, as described above, ozone introduced (enclosed) in the PDP panel reversibly changes to oxygen gas, and ozone may not be detected. However, the method of manufacturing a PDP in the embodiment of the present invention Therefore, it is important that ozone is actively introduced.

  Moreover, ozone is known to absorb ultraviolet rays, and the absorption wavelength of ultraviolet rays by ozone is in the range of 200 nm to 300 nm. The discharge gas containing Xe enclosed in the PDP panel emits ultraviolet light with a wavelength of 147 nm or 173 nm, but it is considered that these emitted ultraviolet light is hardly absorbed by ozone, and the PDP panel brightness The effect on the decline of In addition, as described above, the PDP in the embodiment of the present invention performs sealing (sealing) and evacuation processes using an atmosphere containing ozone. In the embodiment of the present invention, the ozone content is preferably 0.01 ppm to 5% because the concentration is considered to be very low and the atmosphere contains 0.005 ppm of ozone. thinking. Conversely, if the amount of ozone is too large, the discharge may be adversely affected, and oxygen gas changed from ozone by reversible reaction may absorb ultraviolet rays, so 0.01 ppm to 1000 ppm is desirable. . In addition, ozone has a risk of adversely affecting the human body when its concentration is high due to its strong oxidizing power, and the allowable concentration of ozone is set to 0.1 ppm by the Japan Society for Occupational Health (ACGIH). However, as described above, ozone is converted into a harmless gas by reaction with the impurity gas, and the ozone itself returns to oxygen with time, so that the influence is considered to be small depending on the concentration of the impurity gas. However, as described above, the amount of ozone is most preferably offset with impurities, and is preferably about 5%. Also, when actually handling ozone, fortunately, there is a strong odor at concentrations where ozone is toxic, so there is very little risk of exposure to conditions that will unintentionally adversely affect the human body. It is believed that.

  In addition, since ozone is known to be catalytically decomposed on the surface of silica, alumina, ferric oxide, etc., it is preferable to design them so as not to be included in components that come into contact with ozone in the panel of PDP. .

  As described above, in the method for manufacturing the PDP according to the embodiment of the present invention, in the sealing step of sealing the front plate and the rear plate with the sealing member and the exhausting step of exhausting the gas in the sealed panel, At the time of sealing, before exhaust, or at any point during exhaust, ozone, oxygen gas, or a mixed gas of ozone and oxygen gas, that is, a gas containing at least one selected from ozone and oxygen gas It has already been mentioned that it is produced by introducing or flowing the material. In the conventional method of removing adsorbed gas by simply raising the temperature during sealing and exhaust, there are many impurity gases that cannot be completely removed at the sealing and exhaust temperature, as described above. In the method for manufacturing a PDP in the embodiment of the present invention using ozone, the CH-based gas can be decomposed and removed by ozone in the sealing step. In addition, since the ability to remove CH-based gas by ozone can be effective regardless of the influence of the sealing process and the exhaust process, a gas containing at least one kind selected from ozone and oxygen gas is temporarily provided after the sealing process. The exhaust may be performed after introduction or flow. In addition, while exhausting the gas in the PDP panel in the exhaust process, the same processing is performed by simultaneously introducing or flowing a gas containing at least one selected from ozone and oxygen gas into the PDP panel. You can also. In addition, even when the sealing and exhausting steps are continuously performed, the processing may be performed while flowing a gas containing at least one kind selected from ozone and oxygen gas in either the sealing or exhausting step. it can.

  Further, in the PDP manufacturing method according to the embodiment of the present invention, a gas containing any of ozone, oxygen gas, and a mixed gas of ozone and oxygen gas is introduced (encapsulated) into the discharge gas in the discharge gas sealing step after the exhausting step. And the discharge gas is a mixed gas containing at least one kind of rare gas and ozone, oxygen gas, or a mixed gas of ozone and oxygen gas. The decomposition and removal reaction by ozone can also be used for the CH-based impurity gas released by the strong discharge, and the effect of reducing the impurity gas in the tube can be exhibited.

  Since the PDP according to the present invention can suppress the influence of impurity gas that affects the display quality and life characteristics, a high-efficiency and high-quality PDP can be provided, and a large and thin flat panel display device can be provided. The present invention can be applied to large television receivers and public display monitors.

The disassembled perspective view which shows schematic structure of PDP in embodiment of this invention The top view which shows schematic structure of the image display part of PDP in embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front plate 2 Back plate 4 Scan electrode 4a, 5a Transparent electrode 4b, 5b Bus electrode 5 Sustain electrode 6 Display electrode 7 Dielectric layer 8 Protective film 10 Address electrode (data electrode)
DESCRIPTION OF SYMBOLS 11 Base dielectric layer 12 Partition 13 Phosphor layer 14 Discharge gap 15 Discharge cell 16 Non-light emitting area 100 PDP (plasma display panel)

Claims (2)

A plurality of display electrodes are formed and the display electrode is covered with a dielectric layer and a protective film, and the front plate is disposed opposite to the front plate so as to form a discharge space, and is formed in a direction perpendicular to the display electrode. In the plasma display panel comprising a back plate formed with a phosphor layer between the partition walls that form the address electrodes and partition the discharge space, and the discharge space is filled with a discharge gas,
A plasma display panel, wherein the discharge gas contains ozone in a range of 0.01 ppm to 5% . A plurality of display electrodes are formed and the display electrode is covered with a dielectric layer and a protective film, and the front plate is disposed opposite to the front plate so as to form a discharge space, and is formed in a direction perpendicular to the display electrode. In the manufacturing method of the plasma display panel comprising a back plate having a phosphor layer formed between the partition walls that form the address electrodes and partition the discharge space, and the discharge space is filled with a discharge gas,
A sealing step of sealing a panel composed of the front plate and the back plate disposed opposite to each other with a sealing member formed in a peripheral portion; and an exhausting step of exhausting the gas inside the sealed panel,
In the sealing step or the exhausting step, a process of exposing the components inside the panel to a gas containing at least one selected from ozone and oxygen gas,
A method for manufacturing a plasma display panel, wherein ozone is contained in the discharge gas in a range of 0.01 ppm to 5%.

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