JP2011060783A - Plasma display panel and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve image display quality and to stably maintain the image display quality for a long period of time in a plasma display panel used for an image display device, etc. <P>SOLUTION: In a plasma display panel, first and second electrodes constituting a pair of main electrodes are covered with an insulating layer against discharge gas. A protective film 14 is formed as at least a surface layer of the dielectric glass layer 13, the surface layer being in contact with the discharge gas. At least a part of the surface layer is covered with a material having a value of enthalpy lower than standard enthalpies of formation of magnesium hydroxide, magnesium carbonate, magnesium hydrogen carbonate, magnesium nitrate, magnesium sulfate, etc. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plasma display panel used for an image display device or the like and a manufacturing method thereof.

  A conventional plasma display panel is generally configured as shown in FIG.

  This plasma display panel includes a front panel 100 and a back panel 200. In the front panel 100, scan electrodes 102a and sustain electrodes 102b are alternately formed in a stripe shape on a front glass substrate 101, and further covered with a protective film 104 made of a dielectric glass layer 103 and magnesium oxide (MgO). It is formed.

  In the rear panel 200, an address electrode 202 is formed in a stripe shape on a rear glass substrate 201, an electrode protective layer 203 is formed to cover the address electrode 202, and a stripe is formed on the electrode protective layer 203 so as to sandwich the address electrode 202. The barrier ribs 204 are formed in the shape, and the phosphor layer 205 is further provided between the barrier ribs 204. Then, the front panel 100 and the rear panel 200 are bonded together, and a discharge space is formed by enclosing the discharge gas in the space 210 partitioned by the partition wall 204. The phosphor layers are usually arranged in order of phosphor layers of three colors of red, green and blue for color display.

  In the discharge space 210, for example, a discharge gas formed by mixing neon and xenon is normally sealed at a pressure of about 0.67 × 10 5 Pa.

  Next, a driving method of the plasma display panel will be described.

  FIG. 7 is a block diagram showing a configuration of a driving circuit of the plasma display panel.

  The drive circuit includes an address electrode drive unit 220, a scan electrode drive unit 230, and a sustain electrode drive unit 240.

  The address electrode driver 220 is connected to the address electrode 202 of the plasma display panel, the scan electrode driver 230 is connected to the scan electrode 102a, and the sustain electrode driver 240 is connected to the sustain electrode 102b.

  In general, in an AC plasma display panel, a method of expressing gradation by dividing one frame image into a plurality of subfields (SF) is used. In this method, 1SF is further divided into four periods in order to control the discharge of gas in the cell. These four periods will be described with reference to FIG. FIG. 8 shows drive waveforms during 1SF.

  In FIG. 8, in the setup period 250, wall charges are uniformly accumulated in all the cells in the PDP in order to facilitate discharge. In the address period 260, the write discharge of the cells to be lit is performed. In the sustain period 270, the cells written in the address period 260 are turned on and kept on. In the erase period 280, lighting of the cells is stopped by erasing the wall charges.

  In the setup period 250, a higher voltage is applied to the scan electrode 102a than the address electrode 202 and the sustain electrode 102b to discharge the gas in the cell. The charges generated thereby are accumulated on the wall of the cell so as to cancel the potential difference between the address electrode 202, the scan electrode 102a, and the sustain electrode 102b. Therefore, negative charges are generated as wall charges on the surface of the protective film near the scan electrode 102a. In addition, positive charges are accumulated as wall charges on the phosphor layer surface near the address electrodes and the protective film surface near the sustain electrodes. Due to this wall charge, a predetermined wall potential is generated between the scan electrode and the address electrode and between the scan electrode and the sustain electrode.

  In the address period 260, when the cell is turned on, a voltage lower than that of the address electrode 202 and the sustain electrode 102b is applied to the scan electrode 102a, that is, a voltage is applied between the scan electrode and the address electrode in the same direction as the wall potential. Is applied, and a voltage is applied in the same direction as the wall potential between the scan electrode and the sustain electrode, thereby generating a write discharge. As a result, negative charges are accumulated on the phosphor layer surface and the protective film surface, and positive charges are accumulated as wall charges on the protective film surface near the scanning side electrode. As a result, a predetermined wall potential is generated between the sustain and scan electrodes.

  In the sustain period 270, a sustain discharge is generated by applying a higher voltage to the scan electrode 102a than the sustain electrode 102b, that is, by applying a voltage in the same direction as the wall potential between the sustain electrode and the scan electrode. Thereby, cell lighting can be started. Then, pulse emission can be intermittently performed by applying a pulse so that the polarity is alternately switched between the sustain electrode and the scan electrode.

  In the erase period 280, erasing is performed because imperfect discharge is generated by applying a narrow erase pulse to the sustain electrode 102b and the wall charges disappear.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2001-357787 A

  As described above, the plasma display panel uses a driving method that forms wall charges and makes it possible to reduce a voltage value necessary for discharge by using a potential generated thereby. However, when an impurity gas other than the discharge gas is present in the discharge space, or when the protective film is altered by the gas or the like, an effect of erasing the wall charges occurs. Due to this action, a normal applied voltage does not reach the discharge start voltage of the address discharge, and a cell in which lighting / non-lighting is not selected is generated. In other words, sustain discharge does not occur and lighting failure occurs, resulting in non-lighting and flickering during image display.

  Further, this wall charge erasing phenomenon proceeds with increasing degree over time, so that the phenomenon appears remarkably at a place where the order of selecting cells to be lit is late, that is, a place where scanning is slow. As shown in FIG. 8, this phenomenon appears more prominently in a portion where the time from the accumulation of wall charges in the setup period 250 to the address discharge in the address period 260 is long.

  By the way, when displaying a TV picture, it is necessary to finish all sequences within one field = 1/60 [s]. In the future, as the cell structure becomes more precise, the number of scanning lines is increased. Will increase. In other words, this phenomenon becomes even more pronounced.

  Furthermore, the presence of such impurity gas in the discharge space also promotes deterioration of the phosphor and deterioration of wear resistance (sputtering property) due to discharge of the protective film, which means that image display quality is improved. This will lead to accelerated lifespan.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a plasma display panel having a structure effective for preventing the incorporation of impurity gas into the discharge space and a method for manufacturing the same.

  In order to solve such a problem, the present invention provides that at least a part of the surface layer of the protective film is generated as a standard than any of hydroxide, carbonate, nitrate and sulfate of the base material of the protective film. The composition is covered with a substance having a low enthalpy value.

As described above, the present invention is a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer against a discharge gas, and at least the discharge of the insulating layer As a surface layer in contact with the gas, a magnesium oxide [MgO] film is provided, and at least a part of the surface layer of the MgO film includes magnesium hydroxide [Mg (OH) ₂ ], magnesium carbonate [MgCO ₃ ], magnesium hydrogen carbonate [Mg ( An altered layer of the MgO film is formed by being covered with a material having a lower value than the standard enthalpy of formation such as HCO ₃ ) ₂ ], magnesium nitrate [Mg (NO ₃ ) ₂ ], magnesium sulfate [MgSO ₄ ], etc. In addition, it is possible to prevent impurity gas from being taken into the discharge space after the panels are bonded together. There is resolved, improved image display quality, and its good quality will be able to maintain a long life basis.

The perspective view which shows the plasma display panel by one embodiment of this invention (A), (b) is sectional drawing cut | disconnected by the AA 'line of FIG. 1 which shows the example of a protective film, respectively (A), (b) it is a characteristic diagram showing a difference of H ₂ O adsorbed amount and CO ₂ adsorption amount of the MgO film of the present invention and the prior art Characteristics chart showing life comparison of protective film of the present invention and the prior art Characteristic diagram showing change of flicker level with respect to Si concentration in MgO film A perspective view showing a conventional plasma display panel Block diagram showing an image display device configured by connecting a driving circuit to a plasma display panel Time chart showing driving waveform of plasma display panel

  First, the following three points can be considered for the incorporation of the impurity gas into the discharge space.

1. 1. Impurity gas is adsorbed on the protective film on the front panel. 2. Impurity gas is adsorbed on the phosphor on the rear panel. In the case where the exhaust process after bonding the front panel and the rear panel is insufficient In the cases 1 and 2, it can be considered as a substance that adsorbs gas existing in the atmosphere such as H ₂ O and CO ₂ . Especially the situation in 1 is serious.

In the case where the protective film is conventional MgO, it is considered that when such a gas is adsorbed, it is transformed into Mg (OH) ₂ , MgCO _3, etc. by adsorption. These materials require very high energy to dissociate from MgO. Therefore, when there is such a change in the MgO film before the bonding process, it is hardly dissociated in the subsequent heat process such as sealing and exhaust.

However, these Mg (OH) ₂ , MgCO _3, etc. are finally dissociated by energy such as ion bombardment caused by discharge, and are released in the form of H ₂ O, CO ₂ , or their ions. That is, when the image is displayed after the panel is formed, these deteriorated layers are finally released as impurity gases and remain in the discharge space.

  Therefore, the influence of the impurity gas as described above appears as degradation of image display quality and degradation of its life.

Further, when the protective film is grown in such a form that there is an interface perpendicular to the film thickness direction as in the columnar structure, Mg (OH) ₂ and MgCO ₃ are also formed at the interface of the columnar structure. It is thought that it is done. In the altered layer formed at this interface, the protective film is worn by the discharge (sputtered by ion bombardment), and at the same time, dissociation into H ₂ O and CO ₂ proceeds at any time, and the impurity gas into the discharge space Supply will always be made. That is, deterioration of image display quality is promoted with the time used as an image display device.

Therefore, as a fundamental countermeasure against this problem, various image display quality deteriorations as described above are required unless the H ₂ O and CO ₂ protective films are adsorbed to MgO before the bonding process. Can be prevented.

As a method for this purpose, it is considered that it is effective to cover MgO with a substance that is chemically more stable than Mg (OH) ₂ , MgCO _3, etc. before these altered layers are formed.

Therefore, the present inventors have conceived the present invention as a result of searching for a protective film material that does not generate Mg (OH) ₂ and MgCO ₃ as altered layers without adding any new process.

In the above description, only Mg (OH) ₂ and MgCO ₃ are described as altered layers from MgO, but besides these, MgO is Mg (NO ₃ ) ₂ , MgSO _{4 due to} adsorption of gas in the atmosphere. Although alteration to Mg (HCO ₃ ) ₂ or the like is also conceivable, by implementing the present invention, formation of these alteration layers can be similarly prevented and the same effect can be obtained.

  That is, according to the present invention, there is provided a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with a protective film. At least a part of the surface layer of the membrane is covered with a substance having a larger standard generation enthalpy value than any of hydroxide, carbonate, nitrate, and sulfate of the base material of the protective membrane And

  In the present invention, the protective film is magnesium oxide [MgO].

Furthermore, in the present invention, at least a part of the surface layer of magnesium oxide is magnesium hydroxide [Mg (OH) ₂ ], magnesium carbonate [MgCO ₃ ], magnesium hydrogen carbonate [Mg (HCO ₃ ) ₂ ], magnesium nitrate. It is characterized by being covered with a substance having a standard enthalpy value lower than that of either [Mg (NO ₃ ) ₂ ] or magnesium sulfate [MgSO ₄ ].

  In the present invention, at least a part of the surface layer of magnesium oxide is a substance having a standard production enthalpy value lower than −925 kJ / mol, a substance having a standard production enthalpy value lower than −1096 kJ / mol, and a standard production enthalpy value. It is characterized by being covered with a substance lower than −791 kJ / mol or a substance with a standard production enthalpy value lower than −1284 kJ / mol.

In the present invention, at least a part of the surface layer of magnesium oxide is covered with a substance containing phosphorus [P] or silicon [Si]. The substance containing phosphorus is Mg ₃ (PO ₄ ) ₂ , and the substance containing silicon is at least one of MgSiO ₃ and Mg ₂ SiO ₄ .

  According to the present invention, there is provided a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with magnesium oxide. Magnesium contains phosphorus [P]. And the density | concentration of the phosphorus contained in the magnesium oxide exists in the range of 100-15000 ppm, It is characterized by the above-mentioned.

  The concentration of phosphorus contained in the magnesium oxide has a distribution difference with respect to the growth direction of the magnesium oxide film, and the distribution difference in the concentration of phosphorus contained in the magnesium oxide Compared to the body layer side, the concentration on the side in contact with the discharge gas is dense.

  The magnesium oxide film has a multilayer structure of a layer containing phosphorus and a layer not containing phosphorus.

  According to the present invention, there is provided a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with magnesium oxide. Magnesium contains silicon [Si] at a ratio in the range of 10,000 to 15000 ppm.

  Furthermore, in the present invention, there is provided a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with magnesium oxide. Magnesium contains silicon [Si] at a ratio in the range of 500 to 15000 ppm, and the concentration of silicon contained in the magnesium oxide has a distribution difference with respect to the growth direction of the magnesium oxide. The concentration difference of the silicon contained in the magnesium oxide is characterized in that the concentration on the side in contact with the discharge gas is denser than that on the dielectric side. The magnesium oxide film has a multilayer structure of a layer containing silicon and a layer not containing silicon.

  According to the present invention, there is provided a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with magnesium oxide. Magnesium contains phosphorus and silicon. And the density | concentration of the phosphorus and silicon which are contained in the magnesium oxide is characterized by being in the range of 100-15000 ppm of phosphorus and 500-15000 ppm of silicon, respectively.

  Further, the concentration of phosphorus and silicon contained in the magnesium oxide has a distribution difference with respect to the growth direction of the magnesium oxide film, respectively, and the concentration of phosphorus and silicon contained in the magnesium oxide The distribution difference is characterized in that the concentration on the side in contact with the discharge gas is denser than that on the dielectric side. The magnesium oxide film has a multilayer structure of a layer containing phosphorus and silicon, a layer containing either phosphorus or silicon, and a layer not containing phosphorus and silicon.

  Furthermore, the protective film according to the present invention is a protective film disposed on the surface facing the discharge and containing at least one element other than the main constituent material, and the elements other than the main constituent material are dissociated by the energy of the discharge. However, when it reattaches to the surface, it always moves to the surface side facing the discharge. The main constituent material is magnesium oxide, and the element other than the main constituent material is silicon or phosphorus.

  Furthermore, the present invention is characterized in that the protective layer covers an insulating layer that covers the electrodes of the plasma display panel.

  Further, the present invention is a method for manufacturing a plasma display panel, wherein the first and second electrodes constituting the main electrode pair are covered with an insulating layer against a discharge gas, and the insulating layer is covered with a magnesium oxide film. Then, the magnesium oxide film is formed by a vapor deposition method in which pellet-shaped magnesium oxide, pellet-shaped or powder-like phosphorus compound, or pellet-shaped or powder-shaped silicon compound are mixed and heated simultaneously.

  Furthermore, in the manufacturing method of the present invention, the magnesium oxide film is formed by a vapor deposition method in which a sintered body in which powdered magnesium oxide, a powdered phosphorus compound, and a powdered silicon compound are mixed is heated. And

  In the production method of the present invention, the magnesium oxide film is formed by a sputtering method using a sintered body obtained by mixing powder-like magnesium oxide, powder-like phosphorus compound, and powder-like silicon compound as a target. And

According to these present inventions, a plasma display panel can be manufactured without MgO of the protective film forming Mg (OH) ₂ , MgCO _3, etc. of the deteriorated layer, and impurity gas is not taken into the panel. Thus, the image display quality can be improved and the high quality state can be maintained for a long lifetime. Further, as described above, by changing the Si concentration with respect to the growth direction of MgO, a compound of Si and Mg is formed in the surface layer on the side in contact with the MgO discharge gas. OH) ₂ , MgCO ₃ , Mg (NO ₃ ) ₂ , MgSO _{4, and the} like are not formed, and the inside of the surface layer, that is, MgO with less impurities remains in the protective film, so that the electron emission capability is maintained. As a result, the image display quality can be further improved.

  Hereinafter, a plasma display panel according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial perspective view of an AC surface discharge type plasma display panel 1 (hereinafter simply referred to as PDP 1) according to an embodiment of the present invention.

  The PDP 1 generates a discharge in the discharge space 30 by applying a pulsed voltage to each electrode, and transmits visible light of each color generated on the back panel PA 2 side from the main surface of the front panel PA 1 along with the discharge. AC surface discharge type PDP.

  The front panel PA1 has a surface 11a on a front glass substrate 11 in which a plurality of pairs of scanning electrodes 12a and sustaining electrodes 12b are provided in a stripe shape with a discharge gap 12c (one pair is shown in the figure for convenience). A dielectric glass layer 13 is formed as an insulating layer so as to cover the dielectric layer. Further, a protective film 14 made of MgO is formed so as to cover the dielectric glass layer 13.

  This protective film 14 is formed by a manufacturing method as described above, which reduces adsorbed gas and prevents the formation of a deteriorated layer.

  The rear panel PA2 protects the address electrodes on the rear glass substrate 16 arranged in stripes so that the address electrodes 17 are orthogonal to the scan electrodes 12a and the sustain electrodes 12b, and reflects visible light to the front panel side. An electrode protection layer 18 that functions to cover the address electrode 17 is formed. The partition wall 19 extends on the electrode protection layer 18 in the same direction as the address electrode 17 and sandwiches the address electrode 17 therebetween. Further, the phosphor layer 20 is disposed between the partition walls 19.

  The PDP having the above configuration is driven based on the drive waveform shown in FIG. 8 by using the drive circuit shown in FIG. The address electrode 17 is connected to the address electrode driver 220, the scan electrode 12a is connected to the scan electrode driver 230, and the sustain electrode 12b is connected to the sustain electrode driver 240.

  Next, the form of the protective film of the present invention will be described.

  FIG. 2A is a cross-sectional view taken along line AA ′ in FIG. In the prior art, only one layer of magnesium oxide is formed as a protective layer on the dielectric, but in the present invention, a second layer is further formed on the side facing the discharge space of magnesium oxide as the protective film. The protective layer is provided. That is, the protective film 14 is composed of a first protective layer 14a and a second protective layer 14b made of magnesium oxide.

This second protective layer 14b has a standard generation enthalpy value lower than that of Mg (OH) ₂ , MgCO _3, etc., and is a more chemically stable material. This second protective layer 14b is made of magnesium, It is an oxide of silicon, or an oxide of magnesium or phosphorus.

  FIG. 2B shows a case where the magnesium oxide film structure of the protective film is a columnar structure. Also in this case, the second protective layer 14b is formed so as to cover the entire surface of the magnesium oxide corresponding to the first protective layer 14a, as in FIG. That is, the second protective layer 14b is also formed at the interface between these individual columnar structures. In FIG. 2, the second protective layer is illustrated so as to cover the entire side of the magnesium oxide facing the discharge space, but the present invention is not limited to this form and covers at least a part of the first protective layer. Even in this case, the same effect can be obtained.

As described above, by forming the second protective layer on the side of the first protective layer (magnesium oxide) facing the discharge space, Mg (OH) ₂ , MgCO ₃ , Mg (NO ₃ ) ₂ , Altered layers such as MgSO ₄ and Mg (HCO ₃ ) ₂ are not formed.

  3A and 3B show the amounts of adsorption of the protective films of the present invention and the prior art. In this method, each protective film is formed on each glass substrate, and then left for a certain period of time (which is considered to be required during production), and these samples are placed on each sample by a quadrupole mass spectrometer using temperature programmed desorption. The amount of adsorbed was measured. This shows that the amount of adsorption of the protective film made of the MgO + Mg, Si oxide or MgO + Mg, P oxide of the present invention is smaller than that of the conventional protective film made only of MgO.

  In addition, FIG. 4 shows the results of a life test using a PDP manufactured using the three types of protective films shown in FIG. This is the life limit defined by the time during which the voltage required for discharge suddenly increases. According to this, the protective film made of MgO + Mg, Si or MgO + Mg, P oxide of the present invention takes a longer time to reach the life limit than the conventional MgO + protective film. I understand. From these two types of examination results, it is considered that preventing the formation of a deteriorated layer of MgO as a protective film leads to higher display quality and longer life.

This is because the surface of MgO (side facing the discharge space after panel formation) is Mg (OH) ₂ , MgCO ₃ , Mg (NO ₃ ) ₂ , MgSO ₄ , Mg (HCO ₃₎ chemically changed to _2, etc., is considered to H ₂ O in the discharge space after an altered layer thereof is paneled, to be released becomes CO _2, etc. are affected. This is because wall charges originally formed in the setup period 250 are erased by the presence of impurity gases other than the discharge gas.

However, in this invention, the 2nd protective layer is formed in the surface of MgO which is a 1st protective layer. This second protective layer is chemically stable because it has a lower standard enthalpy value than Mg (OH) ₂ , MgCO ₃ , Mg (NO ₃ ) ₂ , MgSO ₄ , Mg (HCO ₃ ) _2, etc. Therefore, these deteriorated layers are not formed. That is, the impurity gas is not released into the discharge space after the panel formation, which has occurred in the prior art. As a result, the problem of erasing wall charges does not occur, leading to a longer product life.

  Table 1 lists the standard production enthalpy values of the substances mentioned in the present invention. In the present invention, the standard generation enthalpy value (kJ / mol) indicates the heat of formation per 1 mol of the compound in the standard state (1 atm, 25 ° C.). That is, it is the heat (reaction heat) generated when a compound reacts from a single component element, and it can be said that a substance with a low standard generation enthalpy is more stable. In addition, when a standard generation enthalpy value for a certain compound is required, it can be examined from a literature such as a chemical manual (extracted from the 4th edition of the Chemical Handbook [edited by the Chemical Society of Japan] in Table 1).

  By the way, if the second protective layer is thick, it is possible to stably prevent the formation of the deteriorated layer. On the other hand, if the second protective layer is thick, the ability of emitting electrons from MgO is inhibited. From such a viewpoint, the film thickness of the second protective layer becomes important. The film thickness of the second protective layer is largely attributed to the concentration of Si contained in MgO, and the film thickness increases as the Si concentration increases.

  FIG. 5 shows the result of visual evaluation of the concentration of Si contained in the MgO film and the level of image display quality as PDP. The numerical value of the visual recognition level indicates “flickering degree”, and the lower the value, the better the display quality. When the visual recognition level 2 is defined as a non-defective product limit, it was found that the Si concentration is preferably 15000 ppm or less. In addition, although said density | concentration examination described only about Si, as a result of examining the same about P, in the case of P, the density | concentration within the range of 100-15000 ppm was effective. In addition, this evaluation is performed under a unique condition in which “wall charge erasure” does not occur.

  Next, a method for manufacturing a PDP will be described.

  First, the production of the front panel PA1 will be described. The scan electrodes 12a and the sustain electrodes 12b are formed on the front glass substrate 11 so as to be alternately arranged. The scan electrode 12a and the sustain electrode 12b are metal electrodes, and are formed by forming a film of platinum by an electron beam evaporation method and then patterning it by a lift-off method. Each scanning electrode 12a and sustain electrode 12b may be formed of a pair of a transparent electrode such as ITO and a metal electrode.

  Next, a dielectric glass layer is formed by printing and baking by a known printing method such as a screen printing method so as to cover the scan electrode 12a and the sustain electrode 12b.

  Next, an MgO protective film 14 is formed on the surface of the dielectric glass layer 13. Specifically, an MgO thin film is deposited on the surface of the dielectric glass layer 13 by electron beam evaporation.

  Next, the production of the back panel PA2 will be described. In the back panel PA2, the address electrodes 17 are formed on the back glass substrate 16, and the electrode electrodes are covered with the electrode protection layer 18, and the partition walls 19 are formed on the surface of the electrode protection layer 18. Then, the phosphor layer 20 is formed. The address electrode 17 is formed on the rear glass substrate 16 by the same method as the scan electrode 12a and the sustain electrode 12b.

The electrode protective layer 18 is formed on the address electrode 17 by printing using a printing method such as a screen printing method and then firing, and is formed of a glass composition similar to the dielectric glass layer 13. The thin film contains titanium oxide (TiO ₂ ) particles.

  The partition wall 19 is formed by applying a partition wall forming raw material by a method such as a screen printing method, a lift-off method, or a sand blasting method, firing the material, and then processing the top of the partition wall.

  The phosphor layer 20 is formed by a method such as screen printing or nozzle spraying. Note that three colors of red, green, and blue are used for the phosphor. For example, the following can be used.

Red phosphor: Y ₂ O ₃ : Eu ³⁺
Green phosphor: Zn ₂ SiO ₄ : Mn ²⁺
Blue phosphor: BaMgAl ₁₀ O ₁₇ : Eu ²⁺
Next, the front panel PA1 and the rear panel PA2 are aligned so that the scan electrodes 12a, the sustain electrodes 12b, and the address electrodes 17 are orthogonal to each other, and the two panels are bonded together. Thereafter, a discharge gas, for example, a He—Xe-based or Ne—Xe-based inert gas is sealed in the discharge space 30 partitioned by the barrier ribs 19 at a predetermined pressure.

  Next, the manufacturing method of the protective film of this invention is demonstrated.

  First, a manufacturing method using Si will be described. A material containing Si is mixed in an MgO vapor deposition source, and a desired film is formed by simultaneously heating in an oxygen atmosphere using a piercing electron beam gun as a heating source. . At this time, due to the unique self-diffusion ability of Si, in an oxygen atmosphere, Si element always moves to the film surface during film growth. For this reason, at the end of film formation, a protective film separated into two layers of MgO, Mg, and Si oxide is obtained.

  At this time, in order to utilize the unique self-diffusion ability of Si as described above, it is necessary to give energy to the substrate rather than during normal film formation. In this embodiment, the substrate temperature is set higher than the normal value, and the oxygen partial pressure is set higher than the normal value.

  In addition to this, for example, there are a method of irradiating the surface of the protective film with ultraviolet rays, a method of forming a film in an ozone atmosphere, a method of shortening the distance between the evaporation source and the substrate, etc. If the method is to apply energy, a protective film having the same structure can be obtained, and the same effect can be obtained.

  Further, the Si concentration contained in MgO is required to be 500 to 15000 ppm in order to obtain a good image display quality as described above. This concentration was estimated from the film analysis after the panel was formed and the emission spectroscopic analysis result of the sample simultaneously formed on the sapphire substrate.

  Furthermore, in the range of Si concentration of 10,000 to 15,000 ppm, the same effect can be obtained even if it exists uniformly in the MgO film. However, in the range of Si concentration of 500 to 10,000 ppm, the growth direction of the MgO film can be obtained. It is desirable that there is a concentration distribution and that the MgO film is densely present on the side in contact with the discharge gas.

  Moreover, the present invention is not limited to the above embodiment, and a pellet obtained by mixing and sintering a powder-like MgO material and a powder-like Si-containing material may be used. Alternatively, the same effect can be obtained by a sputtering method using the same. Moreover, Si can be contained in the protective film in the same manner as described above even when the SiO is contained in the container of the MgO vapor deposition source in the apparatus.

  Next, the production method using P will be described. In this case as well, the vapor deposition method was used as in the case of Si described above. A substance containing P was mixed in an MgO vapor deposition source, and a desired film was formed by heating simultaneously in an oxygen atmosphere using a piercing electron beam gun as a heating source. At this time, like Si, the P element always moves to the film surface during film growth because of the unique self-diffusion ability of P in the oxygen atmosphere. For this reason, at the end of film formation, a protective film separated into two layers of MgO, Mg, and P oxide is obtained.

  At this time, in order to use the peculiar self-diffusion capability of P as described above, it is necessary to give energy to the substrate rather than during normal film formation. In this embodiment, the substrate temperature is set higher than the normal value, and the oxygen partial pressure is set higher than the normal value.

  In addition to this, for example, there are a method of irradiating the surface of the protective film with ultraviolet rays, a method of forming a film in an ozone atmosphere, a method of shortening the distance between the evaporation source and the substrate, etc. If the method is to apply energy, a protective film having the same structure can be obtained, and the same effect can be obtained.

  The concentration of P contained in MgO is effectively 100 to 15000 ppm in order to obtain a good image display quality. This concentration was estimated from the film analysis after the panel formation and the emission spectroscopic analysis result of the sample simultaneously formed on the sapphire substrate as in the case of Si.

  In the above embodiment, the self-diffusion capability of Si and P is used, but a multilayer structure is formed as MgO as the first protective layer, Si as the second protective layer, or a compound of P. But the same effect can be obtained. When these second protective layers are separately formed, the production method is as follows. As described in the related art, immediately after forming MgO to be the first protective layer, the surface of the second protective layer is not exposed to the atmosphere. It is desirable to form a film of such a material.

Further, the example of the above embodiment shows only the method for manufacturing magnesium, silicon oxide, magnesium, and phosphorus oxide. However, the present invention is not limited to this, and Mg (OH) ₂ , MgCO ₃ , Mg ( The effect of the present invention can be obtained if a material having a value lower than the standard enthalpy of formation such as HCO ₃ ) ₂ and Mg (NO ₃ ) ₂ is used as the second protective layer.

  By the way, the part facing the discharge inside the discharge space of the plasma display panel is worn by the sputtering action of the discharge gas. Of course, the Mg, Si oxide layer or the Mg, P oxide layer, which is the second protective layer, is also worn by the sputtering action.

  However, as described above, since Si and P retain their self-diffusion ability, they are diffused to the outermost surface even when they are reattached to the protective film after being sputtered. That is, the second protective layer is always formed even when the life deterioration is in progress. As a result, the effect of the present invention is maintained even while the plasma display panel and the image display device using the panel are used over time.

As described above, the present invention is a plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer against a discharge gas, and at least the discharge of the insulating layer As a surface layer in contact with the gas, a magnesium oxide [MgO] film is provided, and at least a part of the surface layer of the MgO film includes magnesium hydroxide [Mg (OH) ₂ ], magnesium carbonate [MgCO ₃ ], magnesium hydrogen carbonate [Mg ( An altered layer of the MgO film is formed by being covered with a material having a lower value than the standard enthalpy of formation such as HCO ₃ ) ₂ ], magnesium nitrate [Mg (NO ₃ ) ₂ ], magnesium sulfate [MgSO ₄ ], etc. In addition, it is possible to prevent impurity gas from being taken into the discharge space after the panels are bonded together. There is resolved, improved image display quality, and its good quality will be able to maintain a long life basis. This point is industrially useful.

PA1 Front panel PA2 Rear panel 1 Plasma display panel (PDP)
DESCRIPTION OF SYMBOLS 11 Front glass substrate 12a Scan electrode 12b Sustain electrode 12c Discharge gap 13 Dielectric glass layer 14 Protective film 14a 1st protective layer 14b 2nd protective layer 16 Back glass substrate 17 Address electrode 18 Electrode protective layer 19 Partition 20 Phosphor layer 30 Discharge space

Claims (11)

A plasma display panel in which a first electrode and a second electrode constituting a main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with magnesium oxide. A plasma display panel comprising: a concentration within a range of 15000 ppm; and the concentration of silicon contained in the magnesium oxide has a distribution difference with respect to a growth direction of the magnesium oxide film. 2. The plasma display panel according to claim 1, wherein the concentration difference of the silicon contained in the magnesium oxide is denser on the side in contact with the discharge gas than on the insulating layer side. 2. The plasma display panel according to claim 1, wherein the magnesium oxide film has a multilayer structure of a layer containing silicon and a layer not containing silicon. The plasma display panel according to claim 1, wherein the silicon is present in at least one of MgSiO ₃ and Mg ₂ SiO ₄ . A plasma display panel in which first and second electrodes constituting a main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with a magnesium oxide film, wherein the magnesium oxide contains phosphorus and A plasma display panel comprising silicon. 6. The plasma display panel according to claim 5, wherein the magnesium oxide contains 100 to 15000 ppm of phosphorus and 500 to 15000 ppm of silicon. 6. The plasma display panel according to claim 5, wherein the concentration of phosphorus and silicon contained in the magnesium oxide has a distribution difference with respect to the growth direction of the magnesium oxide film. 6. The plasma display panel according to claim 5, wherein the concentration difference of phosphorus and silicon contained in magnesium oxide is denser on the side in contact with the discharge gas than on the insulating layer side. 6. The plasma display according to claim 5, wherein the magnesium oxide film has a multilayer structure of a layer containing phosphorus and silicon, a layer containing either phosphorus or silicon, and a layer not containing phosphorus and silicon. panel. A plasma display panel in which the first and second electrodes constituting the main electrode pair are covered with an insulating layer with respect to a discharge gas, and the insulating layer is covered with a protective film,
The protective film contains at least one element in addition to the main constituent material, and when the main constituent material or the element is dissociated by the energy of discharge and reattaches to the surface of the protective film, the protective film always moves to the surface side facing the discharge. A plasma display panel characterized by the above. The plasma display panel according to claim 10, wherein the element other than the main constituent material is silicon or phosphorus.

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