JP2009099395A - Plasma display panel manufacturing method and apparatus therefor - Google Patents

Abstract

Disclosed is a method for producing a plasma display panel, which can sufficiently remove an altered layer on the surface of a protective layer and has an excellent panel life.
A first conductor plate and a second conductor plate are connected to a front substrate and a rear substrate so that a first conductor plate is in contact with a front substrate and a second conductor plate is in contact with a rear substrate. The first conductor plate 3 and the second conductor are disposed outside and supply gas between the front substrate 1 and the rear substrate 2 through a through hole provided in at least one of the front substrate 1 and the rear substrate 2. A manufacturing method comprising generating a plasma between a front substrate 1 and a back substrate 2 by applying a voltage between the plate 4 and the plate 4.
[Selection] Figure 2

Description

  The present invention relates to a method of manufacturing a plasma display panel used for image display of a television or a computer, and also relates to an apparatus for manufacturing such a plasma display panel. More specifically, the present invention relates to a method for manufacturing a plasma display panel characterized in that an altered layer on the surface of a protective layer is preferably removed, and an apparatus therefor.

  In recent years, the market for large thin displays has expanded. In particular, technological innovations in plasma display panels that can display large-size images with high definition are being actively promoted.

A plasma display panel (hereinafter,: also referred to as "PDP P lasma D isplay P anel") is composed of a counter arranged front and rear substrates. The peripheral portions of the front substrate and the rear substrate are sealed, and a discharge gas (for example, helium or neon) is sealed in a discharge space formed between the front substrate and the rear substrate. The front substrate is generally composed of a glass substrate, a display electrode, a dielectric layer, and a protective layer. More specifically, in the front substrate, display electrodes are formed in stripes on one main surface of the glass substrate, a dielectric layer is formed so as to cover the display electrodes, and on the dielectric layer A protective layer is formed. On the other hand, the back substrate is generally composed of a glass substrate, address electrodes, dielectric layers, barrier ribs, and phosphor layers (red, green and blue phosphor layers). More specifically, in the back substrate, address electrodes are formed in a stripe shape on one main surface of the glass substrate, and a dielectric layer is formed so as to cover the address electrodes. A plurality of barrier ribs are formed on the dielectric layer at regular intervals, and a phosphor layer is formed between adjacent barrier ribs on the dielectric layer. In such a PDP, the phosphor layers of the respective colors are excited by ultraviolet rays generated by applying a voltage in the discharge space, thereby emitting red, green, and blue light to realize color image display.

  The configuration of the PDP will be described in more detail with reference to FIG. For example, a surface discharge type PDP 60 having a three-electrode structure includes an electrode pair composed of a pair of display electrodes 32a and 32b arranged adjacent to each other in parallel on the first glass substrate 31, and an address arranged so as to be orthogonal to the electrode pair. And an electrode 42. As shown in the figure, a first dielectric layer 33 and a protective film 34 are provided on the back surface of the first glass substrate 31. The display electrodes 32a and 32b define a surface discharge cell (display main discharge cell), and one of the display electrodes 32b and the address electrode 42 defines an address discharge cell for selecting lighting or non-lighting of the unit light emitting region. The The phosphor layer 45 provided on the rear substrate is provided so as to cover the inner surface of the second glass substrate 41 including the address electrodes 42 along the partition walls (ribs) 45, and is a surface between the display electrodes 32a and 32b. Emits light by being excited by ultraviolet rays generated by the discharge. The light generated by the fluorescence is extracted in the “display direction” of FIG. 6 and the image display is realized. In the case of performing full color display, so-called three primary color phosphor layers 46R, 46G, and 46B of R (red), G (green), and B (blue) are provided for each pixel (dot) constituting the display screen. It is matched. A second dielectric layer 43 is provided between the phosphor layer 45 and the address electrode 42 (see, for example, Patent Document 1). Usually, each phosphor layer 46R, 46G, 46B is formed by applying and firing a phosphor paste mainly composed of a granular phosphor material having a predetermined light emission color for each color using a screen printing method. The

  Here, the operating voltage of the PDP depends on the secondary electron emission coefficient of the protective layer. Accordingly, it has been proposed to reduce the operating voltage by using an alkaline earth metal oxide (eg, calcium oxide, strontium oxide, barium oxide, etc.) having a work function smaller than that of magnesium oxide as a protective layer. Yes. However, these alkaline earth metal oxides are highly hygroscopic and can adsorb moisture in or around the atmosphere after the protective layer is formed, so that the surface portion of the protective layer is transformed into hydroxide or hydrate. As a result, there is a problem that unstable discharge characteristics are brought about. In addition, even when carbon dioxide is present in or around the atmosphere, the surface portion of the protective layer can be transformed into a carbonic acid compound, and similarly, there is a problem that unstable discharge characteristics are brought about.

  In order to deal with the above problems, a method has been proposed in which the process from the protective layer forming process to the sealing process is continuously performed in a dry atmosphere (see, for example, Patent Document 2).

Further, as another method for removing the altered layer on the surface of the protective layer, a method of plasma-treating the front substrate in a vacuum container after the formation of the protective layer (see, for example, Patent Document 3), and after forming the protective layer, the front substrate is oxygenated A method of performing plasma treatment, ultraviolet irradiation treatment or ion etching treatment (for example, see Patent Document 4), a method of performing aging in a state where the gas in the panel is changed to a cleaning gas having a low Xe partial pressure or a low pressure after the sealing step ( For example, see Patent Document 5).
JP 2002-216620 A JP 2002-231129 A JP 2000-57939 A JP 2004-134095 A JP 2004-134157 A

  However, it cannot be said that the deteriorated layer on the surface of the protective layer has been sufficiently removed in the production of the conventional PDP. The method of continuously performing from the protective layer forming step to the sealing step in a dry atmosphere is intended not to form a deteriorated layer on the surface of the protective layer, but in dry air, moisture (water vapor) or Unless carbon dioxide is contained to some extent and the content is not sufficiently small, an altered layer is formed by exposure for several tens of minutes to several hours (for example, 0.1% in dry air having a dew point of −20 ° C. Water, 0.013% water in dry air with a dew point of −40 ° C., and 0.0011% (11 ppm) water in dry air with a dew point of −60 ° C.). When manufacturing a PDP, since there is generally a process inventory of several hours or more from the protective layer forming step to the sealing step, even if dry air with a very low dew point (−60 ° C. or lower dew point) is used, the quality is changed. Formation of the layer is inevitable.

  Even if the front substrate is plasma-treated in a vacuum container after forming the protective layer, the altered layer is formed again before the plasma-treated front substrate is transported to the sealing device in order to remove the altered layer on the surface of the protective layer. Will be. In order to avoid this, it is necessary to transport the front substrate after the plasma treatment to the sealing device in a vacuum atmosphere, and to perform the sealing step in a vacuum atmosphere. However, the configuration of the transport system and the sealing device is extremely high. It becomes complicated and not easy to implement.

  Similarly, in order to remove the altered layer on the surface of the protective layer, even if the front substrate is subjected to oxygen plasma treatment, ultraviolet irradiation treatment or ion etching treatment after the formation of the protective layer, the front substrate is transferred to the sealing device after such treatment. By the time, the deteriorated layer is formed again. In order to avoid this, it is necessary to transport the treated front substrate to the sealing device in a vacuum atmosphere and perform the sealing process in a vacuum atmosphere, but the configuration of the transport system and the sealing device becomes extremely complicated. Realization is not easy.

  In addition, in order to remove the deteriorated layer on the surface of the protective layer, when aging is performed in a state where the gas in the panel is a cleaning gas having a low Xe partial pressure or a low pressure after the sealing step, a gas having a high Xe partial pressure is used. Although the deteriorated layer can be removed at a higher speed than in the case of aging at, the substance containing moisture and carbon generated from the removed deteriorated layer remains inside the PDP. In this case, the altered layer is removed only in the vicinity of the display electrode, and the altered layer remains on the surface of the protective layer away from the display electrode. Therefore, the discharge characteristics are gradually changed due to the influence of the remaining substance, which causes a problem that the panel life is shortened.

  The present invention has been made in view of the above circumstances. That is, the subject of this invention is providing the manufacturing method and apparatus of a plasma display panel which can fully remove the alteration layer on the surface of a protective layer, and was excellent in panel lifetime.

In order to solve the above problems, the present invention is a method of manufacturing a plasma display panel,
(I) preparing a front substrate on which a first electrode, a first dielectric layer and a protective layer are formed on a first glass substrate; and a second electrode, a second dielectric layer, a partition wall and a second glass substrate Preparing a back substrate on which a phosphor layer is formed;
(Ii) applying a glass frit to the front substrate or the back substrate;
(Iii) a step of disposing the front substrate and the rear substrate so as to face each other so that the glass frit is positioned between the front substrate and the rear substrate;
(Iv) disposing the first conductor plate and the second conductor plate outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate;
(V) While supplying gas between the front substrate and the rear substrate through a through hole provided in at least one of the front substrate and the rear substrate, a voltage is applied between the first conductor plate and the second conductor plate. Applying and generating plasma between the front substrate and the back substrate,
(Vi) a step of sealing the front substrate and the rear substrate by melting the glass frit; and (vii) after exhausting gas existing in a space between the front substrate and the rear substrate, the front substrate and the rear substrate. A manufacturing method comprising the step of enclosing a gas containing Xe in a space between the two.

  The present invention is characterized in that, during the manufacture of a plasma display panel, the altered layer on the surface of the protective layer of the front substrate is removed by generating plasma between the front substrate and the rear substrate disposed opposite to each other. In particular, the present invention is characterized in that plasma is generated by applying a voltage between a first conductor plate and a second conductor plate provided outside the front substrate and the rear substrate, and the altered layer is removed.

  As used herein, the term “conductor plate” substantially means a member having conductivity, and its appearance does not necessarily need to be “plate-like”, but a thicker form or a thinner sheet. The shape may be a shape. The size of the main surface of the conductor plate (in other words, “surface that will be in contact with the front substrate or the back substrate”) is preferably large to some extent, and the front substrate and the back substrate face each other. It is preferable to have the above area (in other words, when the front substrate and the back substrate which are arranged to face each other are overlapped with each other, the main surface of the conductor plate has an area larger than the overlapping region. Preferably).

  In certain preferred embodiments, the protective layer is comprised of at least one layer (ie, “single layer” or “multiple layers”), each of which comprises magnesium oxide, calcium oxide, strontium oxide and It comprises at least one selected from the group consisting of barium oxide. In this case, a method for manufacturing a plasma display panel with a low driving voltage is realized.

  In the step (v), it is preferable to apply a pulse voltage or a high frequency voltage between the first conductor plate and the second conductor plate. Thereby, plasma can be generated relatively easily.

  In the step (v), it is preferable that the first conductor plate is electrically connected to “a power source used for applying a voltage” and the second conductor plate is grounded (or grounded). Thereby, sputtering on the surface of the protective layer can be promoted, and the altered layer on the surface of the protective layer can be removed in a shorter time. The term “sputtering” as used herein substantially means a phenomenon in which accelerated ions collide with the surface of the protective layer when the plasma is generated, and the altered layer is blown off and removed.

  Furthermore, in the step (v), it is preferable to supply a gas containing a rare gas between the front substrate and the rear substrate. Thereby, plasma can be generated with a low applied voltage. The rare gas is more preferably helium gas in that plasma can be generated with a lower applied voltage.

  In a preferred embodiment, in the step (vi), the front substrate and the rear substrate are supplied while supplying a gas containing almost no water vapor (for example, a gas containing 0 to 10 ppm of water vapor) between the front substrate and the rear substrate. Heat. Thereby, recontamination of the surface of the protective layer from which the altered layer is removed and cleaned can be effectively suppressed. In particular, if dry air is used as a gas containing almost no water vapor, a more inexpensive method for manufacturing a plasma display panel can be realized.

  In another preferable aspect, in the step (vi), the front substrate and the rear substrate are heated while supplying a gas containing 0 to 10 ppm of carbon dioxide between the front substrate and the rear substrate. Thereby, recontamination of the surface of the protective layer from which the altered layer is removed and cleaned can be effectively suppressed.

The present invention also provides an apparatus for carrying out the method for manufacturing the plasma display panel. Such a manufacturing apparatus of the present invention comprises:
A first conductor plate and a second conductor plate,
A holding device for holding the first conductor plate and the second conductor plate outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate;
A gas supply device for supplying gas between the front substrate and the rear substrate through a through hole provided in at least one of the front substrate and the rear substrate, and between the first conductor plate and the second conductor plate A manufacturing apparatus comprising a power source for applying a voltage.

  Such a manufacturing apparatus of the present invention has a component that enables generation of plasma between a front substrate and a back substrate that are arranged to face each other when manufacturing a plasma display panel. It is characterized by having a component that allows a gas to flow continuously between them.

  In the manufacturing apparatus of the present invention, the power supply can apply a high-frequency voltage between the front substrate and the back substrate, or “pulse power supply that can apply a pulse voltage between the front substrate and the back substrate”. A “high frequency power source” is preferable. Thereby, plasma can be generated relatively easily.

  In a preferred aspect, the first conductor plate is electrically connected to the power source, while the second conductor plate is grounded. Thereby, when a voltage is applied between the front substrate and the back substrate, sputtering of the surface of the protective layer can be promoted, and the altered layer on the surface of the protective layer can be removed in a shorter time.

  As described above, in the method for manufacturing a plasma display panel and the apparatus therefor according to the present invention, the altered layer on the surface of the protective layer can be removed during the manufacture of the plasma display panel, so that a plasma display panel having an excellent panel life can be obtained. it can.

BEST MODE FOR CARRYING OUT THE INVENTION

  In the following, the present invention will be described in more detail. First, a plasma display panel manufacturing method according to the present invention will be described, and then a plasma display panel manufacturing apparatus according to the present invention will be described.

  The method for manufacturing a plasma display panel according to the present invention includes a step for removing the altered layer on the surface of the protective layer.

  First, in step (i), a front substrate (or a surface plate) in which a first electrode, a first dielectric layer, and a protective layer are formed on a first glass substrate is prepared / prepared, and on the second glass substrate. A back substrate (or back plate) on which the second electrode, the second dielectric layer, the barrier ribs, and the phosphor layer are formed is prepared / prepared.

When preparing the front substrate, first, a first electrode is formed on the first glass substrate by, for example, sputtering or firing, and a dielectric precursor material is applied on the first electrode, followed by firing and the like. A body layer is formed. The first glass substrate is not particularly limited as long as it is a transparent and insulating substrate (thickness is, for example, about 1.0 mm to about 3 mm) used for manufacturing a general PDP, for example, a float glass substrate, It may be a soda lime glass substrate, a lead alkali silicate glass substrate, a borosilicate glass substrate, or the like. The first electrode is formed by arranging a plurality of stripes in parallel on the first substrate. For example, the first electrode is a display electrode composed of a scan electrode and a sustain electrode (thickness is about 1 μm to about 50 μm, for example). Preferably there is. In this case, the scan electrode and the sustain electrode are respectively a transparent electrode (an electrode through which visible light generated in the phosphor layer passes) which is a transparent conductive film made of indium oxide (ITO) or tin oxide (SnO ₂ ), and the like. The bus electrode (electrode for lowering the resistance of the display electrode and imparting conductivity in the longitudinal direction of the transparent electrode) generally formed on the transparent electrode. Further, the precursor material of the first dielectric layer is not particularly limited as long as it is a dielectric material used in the production of a general PDP. For example, glass powder and a cellulose or acrylic binder resin (thickening agent) Agent resin) and an organic solvent such as alcohol or ester may be used as a paste or sheet material. The thickness of the first dielectric layer is, for example, about 5 μm to about 50 μm. After forming the first dielectric layer, a protective layer (thickness: 0.5) is formed by forming a film made of magnesium oxide or the like by, for example, an electron beam evaporation (EB evaporation) method so as to cover the dielectric layer. ˜1.5 μm). Such a protective layer is typically composed mainly of magnesium oxide, but may be one obtained by adding a trace amount of elements (such as silicon and / or aluminum) to the protective layer. The protective layer may be composed of a single layer or may be formed by laminating a plurality of layers (for example, it may be a protective layer composed of two or three layers). The main component of the protective layer is not limited to magnesium oxide, but may be calcium oxide, strontium oxide and / or barium oxide. In other words, the protective layer may be formed from at least one component selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide. Even when an alkaline earth metal oxide (that is, calcium oxide, strontium oxide or barium oxide) having a work function smaller than that of magnesium oxide is used as a material for the protective layer, stable discharge characteristics can be obtained. Note that can be obtained.

In preparing the rear substrate, first, a second electrode is formed on a second glass substrate, a dielectric precursor material is applied thereon, and a second dielectric layer is formed by firing or the like. Next, barrier ribs made of low-melting glass are formed in a predetermined pattern, and a phosphor layer is formed by applying and firing a phosphor material between the barrier ribs. The second glass substrate is not particularly limited as long as it is a transparent and insulating substrate (thickness is, for example, about 1.0 mm to about 3 mm) used for manufacturing a general PDP. For example, a float glass substrate, It may be a soda lime glass substrate, a lead alkali silicate glass substrate, a borosilicate glass substrate, or the like. A plurality of second electrodes are formed in stripes on the second substrate, and are, for example, address electrodes (data electrodes) (thickness is about 1 to 4 μm, for example). The address electrode is provided for the purpose of selectively discharging each discharge cell. Such an address electrode can be formed from a conductive paste mainly composed of silver using a screen printing method. In addition, the address electrode is formed by applying a photosensitive paste mainly composed of silver by a die coating method or a printing method, drying at about 100 ° C. to about 200 ° C., and then patterning by a photolithography method in which exposure and development are performed. Can also be formed. Such address electrodes are finally subjected to baking at about 400 to about 700 ° C. after application and drying. The precursor material of the second dielectric layer is not particularly limited as long as it is a dielectric material used for manufacturing a general PDP. For example, glass powder and a cellulose-based or acrylic-based binder resin (thickener resin) ) And an organic solvent such as an alcohol or ester, may be a paste-like or sheet-like raw material. The thickness of the second dielectric layer is, for example, about 5 μm to about 50 μm. A phosphor layer is formed on the second dielectric layer (thickness is about 5 to about 50 μm, for example). The phosphor layer is provided for the purpose of converting ultraviolet rays emitted by the discharge into visible light. Such a phosphor layer has red, green and blue phosphor layers as structural units, each of which is separated by a partition wall. The barrier ribs are formed for the purpose of partitioning the discharge space for each address electrode. Here, the phosphor layer is composed of phosphor powder, binder resin (for example, polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer, acrylic acid ester polymer, etc.) and an organic solvent (for example, ketones such as methyl ethyl ketone, toluene, etc. By applying a paste raw material consisting of an aromatic hydrocarbon of the above, a glycol ether such as propylene glycol monomethyl ether) by a die coating method, a printing method, a dispensing method or an ink jet method, and then subjecting to drying at about 100 ° C. Form. The phosphor powder will be described. For example, examples of the red phosphor powder include Y ₂ O ₃ : Eu, YVO ₄ : Eu, Y ₂ O ₃ S: Eu, and the like. As the green phosphor powder, Zn ₂ GeO ₂ : M, BaAl ₁₂ O ₁₉ : Mn, LaPO ₄ : Tb and the like can be mentioned, and examples of blue phosphor powder include Sr ₅ (PO ₄ ) ₃ Cl: Eu, BaMg ₂ Al ₁₄ O _24. : Eu etc. can be mentioned. The barrier ribs are formed on the second dielectric layer in a stripe shape or in a cross shape, but are made of a low melting point glass material (for example, lead oxide-boron oxide-silicon oxide system, lead oxide-boron oxide-silicon oxide-oxide). Glass powders such as zinc), fillers (eg, oxide ceramics), binder resins (eg, polyvinyl alcohol, polyvinyl butyral, methacrylate polymer, acrylate polymer) and organic solvents (eg, methyl ethyl ketone) Paste raw materials containing ketones, aromatic hydrocarbons such as toluene, glycol ethers such as propylene glycol monomethyl ether, etc.) are applied by a die coating method or a printing method and subjected to drying at about 100 ° C. to 200 ° C. After that, patterning is performed by photolithography that exposes and develops It is then formed by subjecting the firing about 400 ° C. ~ about 700 ° C.. The partition walls can also be formed by using a sandblast method, an etching method, a molding method, or the like.

  In step (ii), a glass frit (or “seal frit”) is applied to the front substrate or the back substrate. The applied glass frit functions to seal the periphery of the front substrate and the rear substrate in a “sealing step” to be performed later. Therefore, such a glass frit is generally applied to the peripheral portion of the front substrate or the rear substrate. The glass frit used is not particularly limited as long as it is used for the same purpose in the production of a general PDP. For example, a low-melting glass material (for example, lead oxide-boron oxide-silicon oxide system, lead oxide-oxidation) A glass frit made of a boron-silicon oxide-zinc oxide system or the like may be used. The thickness of the glass frit applied to the peripheral portion of the front substrate or the back substrate is preferably about 100 to 140 μm, and the width is preferably about 3 to 10 mm.

  In the step (iii), the front substrate and the rear substrate are arranged to face each other so that the coated glass frit is located between the front substrate and the rear substrate. That is, the front substrate and the back substrate are bonded to each other through the glass frit. In other words, the front substrate and the rear substrate are disposed so that the protective layer and the phosphor layer face each other, and more specifically, the display electrode and the address electrode are orthogonal to each other. In addition, the front substrate and the rear substrate are arranged in a substantially parallel positional relationship. The distance between the front substrate and the rear substrate arranged opposite to each other (that is, the gap width) depends on the thickness of the applied glass frit and the like, but is preferably 100 to 1000 μm, and more preferably 300, for example. ˜800 μm.

  In step (iv), the first and second conductor plates are disposed outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate (FIG. 1). In other words, the “first and second conductor plates” and the “front and back substrates” are overlapped in parallel so that the front substrate and the back substrate are on the inside and the two conductor plates are on the outside. The first conductor plate and the second conductor plate are not particularly limited as long as they are made of a conductive material. For example, the first conductor plate and the second conductor plate are made of at least one material selected from the group consisting of copper, aluminum, silver and gold. ing. Although there is no restriction | limiting in particular in the thickness of a 1st conductor plate and a 2nd conductor plate, Preferably it is 0.1-10 mm, More preferably, it is 0.5-2 mm. The size of the main surface of the first conductor plate and the second conductor plate (in other words, “surface that will be in contact with the front or back substrate”) is preferably such that the front substrate and the back substrate face each other. More preferably, it has an area equal to or larger than the “substrate region located inside the applied glass frit” that forms a substantially closed space after sealing.

  In the step (v), in a state where gas is blown between the front substrate and the back substrate through a through hole provided in at least one of the front substrate and the back substrate, the first conductor plate and the second conductor plate are A voltage is applied between them (that is, a potential difference is formed between the first conductor plate and the second conductor plate) to generate plasma in the space between the front substrate and the rear substrate. The plasma generated here is desirably a stable non-equilibrium plasma. The applied voltage is preferably 200 to 2000V, more preferably 500 to 1000V. Since plasma generation is relatively easy, a pulse voltage or a high frequency voltage may be used as the applied voltage. The pulse frequency in the pulse voltage is preferably 1 kHz to 1 MHz, and the pulse width is preferably 0.5 μs to 0.5 ms. The “high frequency” in the high frequency voltage substantially means a frequency of about 100 kHz to 100 MHz.

  Ions in the plasma are accelerated so as to travel straight toward the front substrate and the rear substrate with energy corresponding to the difference between the plasma potential and the floating potential, and collide with the protective layer, the barrier ribs, the phosphor layer, and the like. The collision energy is considered to be about several to 20 eV. Due to this collision, the altered layer on the surface of the protective layer is removed by sputtering, but many of the sputtered particles are decomposed in the gas phase, and finally, between the front substrate and the rear substrate. With the continuous gas flow provided, it is discharged out of the substrate. In this way, the surface of the protective layer can be cleaned. Although the glass frit applied in the step (ii) exists between the front substrate and the rear substrate, the step (v) does not perform the sealing process for melting the glass frit by heating. Therefore, it should be noted that the continuously blown gas can continuously flow out to the outside through the gap at the peripheral edge of the substrate.

  From the viewpoint of further promoting the sputtering of the surface of the protective layer, it is preferable that the first conductor plate is electrically connected to the power source and the second conductor plate is grounded. More specifically, the first conductor plate is electrically connected to the hot side of the power supply (that is, the “non-earth side” or “voltage supply side”), while the second conductor plate is grounded. It is preferable. Thereby, the altered layer on the surface of the protective layer can be removed in a shorter time.

  “Through hole” for blowing gas can be any shape, form, and size as long as it allows gas to flow continuously from the outside between the front substrate and the rear substrate that are opposed to each other. (For example, in the case of a circular through-hole, the diameter size is about 2 to 5 mm), but the through-hole does not interfere with image display of the completed PDP. It is preferable to be located in a peripheral portion of the front substrate (or first glass substrate) or the rear substrate (or second glass substrate) that is not a part. The number of through holes is not limited to one, and a plurality of through holes may be provided as necessary. The through holes can be formed by an appropriate method such as drilling or laser processing after preparing the front substrate or the back substrate, for example. For example, in the case where the through hole is provided on the back substrate, it is preferable to provide the through hole in a stage after the phosphor paste material is applied and dried (the glass frit is applied after the through hole is provided). Will be done).

The gas to be supplied (that is, “the gas blown through the through-hole”) is helium gas (He), neon gas (Ne), argon gas (Ar), krypton gas because plasma can be generated with a low applied voltage. It is preferably at least one kind of rare gas selected from the group consisting of (Kr), xenon gas (Xe) and radon gas (Rn). Among rare gases, helium gas is more preferable because plasma can be generated with a lower applied voltage. When helium gas is used, ions that collide with the protective layer when plasma is generated can be He ⁺ ions. Since such helium gas is an inert gas, it has not only a very low possibility of causing chemical alteration of the protective layer, but also has an advantage that atmospheric pressure discharge can be generated at a low voltage. If the flow rate of the supplied gas is too small, the plasma may shift to unstable arc discharge, which not only makes control difficult, but also causes “unevenness” in the removal of the deteriorated layer, Conversely, too much flow rate is disadvantageous in terms of cost. Therefore, the flow rate of the supplied gas is preferably about 100 sccm to 10 SLM.

  In step (vi), the glass frit is melted to seal the front substrate and the rear substrate. Prior to this step, the voltage generation between the first conductor plate and the second conductor plate is stopped to stop plasma generation. Then, the front substrate and the rear substrate that are arranged to face each other are put into a sealing furnace, and the front substrate and the rear substrate are heated. Thereby, the glass frit is melted, and the front substrate and the rear substrate are joined in an airtight manner. The heating temperature is not particularly limited as long as the glass frit can be melted (that is, it may be a “sealing temperature” used in manufacturing a general PDP).

  In this step (vi), it is preferable to change the gas supplied between the front substrate and the rear substrate facing each other from helium gas to dry gas after plasma generation is stopped (that is, dry gas It is preferable to start blowing). At this time, it is desirable to start blowing the dry gas immediately after the supply of helium gas is stopped so that the atmosphere does not enter between the substrates arranged opposite to each other. Alternatively, blowing of dry gas may be started before stopping the supply of helium gas. And it is preferable to heat and seal the front substrate and the back substrate while blowing dry gas. In some cases, the nitrogen gas blowing amount needs to be reduced or substantially zero at a temperature equal to or higher than the softening point of the glass frit so that the internal pressure between the two substrates does not increase excessively. is there.

  The above-mentioned dry gas is preferably a gas that does not contain any water (water vapor), but may contain a small amount of water (water vapor), and 0-10 ppm of water (water vapor), for example 0 ˜1 ppm of water (water vapor) may be contained. Thereby, the recontamination of the “surface of the protective layer from which the altered layer has been removed and cleaned” can be effectively suppressed. The “amount of water contained in the gas (ppm)” here represents the volume ratio of the water (water vapor) in the total volume of the gas (standard state at 0 ° C. and 1 atm) in parts per million. It is a value obtained by measuring with a conventional dew point meter. Since nitrogen gas is relatively expensive, it is possible to make an inexpensive manufacturing process by using dry air as the dry gas. Similarly, the dry gas is preferably a gas that does not contain any carbon dioxide, but may contain a small amount of carbon dioxide, and the gas may contain 0-10 ppm carbon dioxide components, such as 0-1 ppm carbon dioxide. A carbon component may be included. The carbon dioxide content (ppm) mentioned here is the volume fraction of carbon dioxide in the total volume of gas (standard state at 0 ° C. and 1 atm) expressed in parts per million, and is a conventional non-dispersion. This refers to the value obtained by measurement by the type infrared absorption method (NDIR) (“NDIR” means that carbon dioxide molecules absorb infrared rays (wavelength: 4.26 μm) and This is a method for obtaining the carbon dioxide concentration from the absorbed amount). If the flow rate of the blown dry gas is too small, external air may be mixed, and conversely, if the flow rate is too large, it is disadvantageous in terms of cost. Therefore, the flow rate of the dry gas used in the blowing in the step (vi) is preferably about 20 sccm to 10 SLM.

In the step (vii), after the gas existing in the space between the front substrate and the back substrate is exhausted, a gas containing Xe is sealed between the front substrate and the back substrate. Specifically, the space between the two substrates is kept in a vacuum state (for example, two substrates) while holding the two substrates subjected to the sealing process at a slightly lower temperature (temperature at which the glass frit solidifies) than at the time of sealing. Is exhausted so that the space between the substrates is under a pressure of about 1.0 × 10 ^{−6 to} 1.0 × 10 ⁻² Pa. After the evacuation step is completed, the two substrates are cooled to approximately room temperature, and then a mixed gas of Xe and Ne is introduced between the front substrate and the rear substrate (encapsulation process). The gas introduction is stopped when a predetermined pressure is reached. The gas used for sealing is not limited to a mixed gas of Xe and Ne. For example, only Xe gas may be sealed or a gas mixed with He may be sealed.

Next, a plasma display panel manufacturing apparatus according to the present invention will be described with reference to FIG. The manufacturing apparatus of the present invention
A first conductor plate 3 and a second conductor plate 4;
The first conductor plate 3 and the second conductor plate 4 are held outside the front substrate 1 and the rear substrate 2 so that the first conductor plate 3 is in contact with the front substrate 1 and the second conductor plate 4 is in contact with the rear substrate 2. Holding device, to
A gas supply device for supplying gas between front substrate 1 and rear substrate 2 through a through hole (not shown) provided in at least one of front substrate 1 and rear substrate 2, and a first conductor plate 3 and a second power supply plate 4 for applying a voltage between the second conductor plate 4
It has.

  As shown in FIG. 2, the first conductor plate 3 and the second conductor plate 4 are arranged so that the front substrate 1 and the rear substrate 2 arranged to face each other can be sandwiched from the outside. The materials, thicknesses, main surface sizes, and the like of the first conductor plate 3 and the second conductor plate 4 have already been described above in the manufacturing method of the present invention, and a description thereof will be omitted to avoid duplication.

  The holding device is preferably a “clip member 5 having a spring force” as shown in FIG. 2, for example. The clip member 5 is preferably provided so as to sandwich the peripheral portions of the first conductor plate 3 and the second conductor plate 4. With such clip member 5, the first conductor plate 3 and the second conductor plate 4 are pressed against the front substrate 1 and the back substrate 2, respectively. The clip member 5 does not have to be one, and a plurality of clip members 5 may be provided so that the front substrate 1 and the rear substrate 2 are pressed evenly.

  The gas supply device preferably includes a gas supply source (not shown), a pipe 8, a chuck head 9, a tip pipe 6, and a frit ring 7. The tip tube 6 is pressed against the back substrate through a frit ring 7 in accordance with a through hole (not shown) provided in the back substrate. A chuck head 9 constituting a tip portion of the pipe 8 is connected to the tip of the tip tube 6. A water-cooled pipe / seal mechanism (not shown) is arranged in the chuck head 9 and is configured so as to have a hermetically sealed structure even when the tip pipe 6 and the pipe 8 are heated to the sealing temperature. Has been. For example, a gas supply source (not shown) such as a high-pressure gas cylinder is connected to the pipe 8 so that a rare gas such as helium, neon, argon, krypton, xenon, or radon or nitrogen gas can be supplied. Yes. The gas supply device may be provided with a flow meter or a fan as necessary.

  If the power supply 10 is a power supply for applying a voltage between the 1st conductor board 3 and the 2nd conductor board 4, there will be no restriction | limiting in particular. Preferably, a pulse power source or a high frequency power source can be used as the power source 10. It is preferable that the first conductor plate 3 is electrically connected to the high frequency power supply 10 while the second conductor plate 4 is grounded. Specifically, it is as follows. For example, when a high frequency power source is used as the power source 10, a high frequency voltage having a frequency of 100 kHz to 100 MHz (for example, about 13.56 MHz) is supplied to the base 13 via the connector 11 and the copper plate 12 (or copper wire 12). The pedestal 13 and the conductor plate 3 in close contact with the front substrate 1 are in an electrically conductive state. An impedance matching circuit (not shown) is provided between the high frequency power supply 10 and the connector 11. The clip member 5 is grounded via the copper plate 14 (or copper wire 14). Here, the one end portion 5a of the clip member 5 and the conductor plate 4 brought into close contact with the back substrate 2 are in an electrically conductive state. On the other hand, the other end portion 5b of the clip member 5 and the conductor plate 3 brought into close contact with the front plate 1 are electrically insulated by an insulating member 15 made of ceramics.

  Various elements including the front substrate 1, the rear substrate 2, the first conductor plate 3, and the second conductor plate 4 can be housed in a shield case 16 made of a mesh-like metal so as not to leak high frequency noise. preferable. In this case, the shield case 16 is grounded. Further, it is preferable that an insulating plate 17 is provided between the pedestal 13 and the shield case 16 so that a high-frequency voltage is not applied to the shield case 16.

  Next, the manufacturing method of the present invention will be described based on two embodiments for further understanding of the present invention.

(Embodiment 1)
FIG. 3 is a flowchart showing a schematic configuration of the manufacturing process of the PDP in Embodiment 1 of the present invention. The manufacturing method of the present invention will be described with reference to FIG. The step of preparing the front substrate includes sub-steps of electrode formation, dielectric layer formation, and protective layer formation. On the other hand, the process of preparing the rear substrate includes sub-steps of electrode formation, dielectric layer formation, partition wall formation, and phosphor layer formation, and a sub-step of applying glass frit. Each of these sub-steps includes well-known sputtering methods, vapor deposition methods, photolithography methods, screen printing methods, die coating methods, sand blasting methods and other thin film / thick film forming technologies, microfabrication technologies, and drying / firing methods. It can be realized by a thermal process. After the front substrate and the rear substrate prepared in this way are aligned (positioned) in the alignment apparatus, “two sheets having an area larger than the overlapping portion when the front substrate and the rear substrate are bonded to each other” ”And“ front substrate and rear substrate ”are stacked in parallel so that the front substrate and the rear substrate are on the inside, and the two conductor plates (ie, the first conductor plate and the second conductor plate) are on the outside. Match. At this time, the two conductive plates are overlapped so as to be pressed against the front substrate and the rear substrate. Next, in order to adhere these four thin plates, a clip member as a holding device is attached. Further, a chip tube is attached in accordance with a through hole provided in the back substrate. From the formation of the protective layer to this step, since the protective layer is exposed to the atmosphere, an altered layer may be formed on the surface of the protective layer. Next, a helium gas is blown between the front substrate and the rear substrate through a chip tube through a through hole provided in the rear substrate, and a voltage is applied between the two conductor plates to cause a gap between the front substrate and the rear substrate. Generate plasma. The ions in the plasma are accelerated and moved toward the front substrate and the rear substrate with energy corresponding to the difference between the plasma potential and the floating potential (moving in a direction substantially perpendicular to the substrates), and the front surface. Colliding with the substrate and the back substrate. Due to this collision, the altered layer on the surface of the protective layer formed on the front substrate is removed by sputtering. Most of the sputtered particles are decomposed in the gas phase, and are discharged to the outside through a gap between the front substrate and the back substrate by the flow of gas blown between the front substrate and the back substrate. After the deteriorated layer is sufficiently removed, the voltage application between the two conductor plates is stopped to stop the plasma generation. Then, the gas supplied between the front substrate and the rear substrate is changed from helium to nitrogen. While supplying nitrogen gas, four thin plates (ie, front and back substrates, first and second conductor plates) fixed with clip members are put into a sealing furnace and heated to melt the glass frit. Then, the substrate sealing process is performed. Next, the gas between the two substrates is evacuated so that the two substrates are in a vacuum atmosphere while being held at a temperature slightly lower than that at the time of sealing. After the evacuation step is completed, the two substrates are cooled, and after reaching room temperature, a mixed gas of Xe and Ne is introduced between the front substrate and the rear substrate, and the gas is introduced at a predetermined pressure. Stop. Eventually, when the tip tube is cut, the PDP is completed.

  In the PDP obtained through such a manufacturing process, the altered layer on the surface of the protective layer is removed when plasma is generated, and the gas flowing between the front substrate and the rear substrate immediately after the plasma is stopped is changed from helium gas. Since it is changed to nitrogen gas, no air is mixed between the front substrate and the rear substrate. And since sealing is performed in a state where the space between the front substrate and the rear substrate is filled with nitrogen gas, the altered layer is not formed again on the surface of the protective layer. In addition, since the plasma is generated by applying a voltage between two conductive plates having an area larger than the overlapping portion when the front substrate and the rear substrate are bonded together, the plasma is generated not only in the vicinity of the display electrode but also away from the display electrode. The altered layer on the surface of the protective layer can also be removed. In addition, since a PDP in which moisture, carbon dioxide, etc. are hardly adsorbed not only on the surface of the protective layer but also on the partition walls of the back substrate and the surface of the phosphor layer can be manufactured, It contains almost no gas that causes deterioration or deterioration of the surface of the protective layer, such as moisture and carbon dioxide. As a result, even when the PDP is driven for a long time, a change in the discharge voltage, luminance, etc. is small, and a PDP having an excellent panel life is realized.

  A further advantage of the present invention is that “cracking” hardly occurs in the front substrate and the rear substrate. That is, in the present invention, when the front substrate and the back substrate are bonded, a voltage is generated between the two conductive plates having an area equal to or larger than the overlapping portion, so that the plasma is generated. The whole is heated relatively uniformly by the plasma, and the substrate is not easily cracked by a local thermal gradient. In addition, the PDP obtained by the present invention has no alteration layer on the surface of the protective layer and has very little gas adsorption on the surface of the back substrate. Therefore, there is an effect that aging is almost unnecessary or an extremely short time is required.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is an enlarged cross-sectional view showing a state of four thin plates immediately before plasma generation, nitrogen gas blowing start, and sealing in Embodiment 2 of the present invention. FIG. 4 is an enlarged view of the outer edge portions of the front substrate 1 and the rear substrate 2. The configurations of the front substrate 1, the rear substrate 2, the first conductor plate 3, the second conductor plate 4, the clip member 5, and the insulating member 15 in FIG. 3 are the same as those shown in FIG.

  A partition wall 18 is formed on the surface of the back substrate 2. A glass frit 19 for sealing the front substrate 1 and the rear substrate 2 is formed in a peripheral region of the rear substrate 2 without a partition wall. On the outside of the glass frit 19, a dummy frit 20 formed to be thicker than the partition wall height (100 to 140 μm) and the glass frit thickness (100 to 140 μm) is provided. As can be seen with reference to the plan view of FIG. 5 showing the frit formation arrangement, the glass frit 19 is a continuous stretch so as to surround the overlapping portion when the front substrate 1 and the rear substrate 2 are bonded together. It is formed so as to constitute a ring. On the other hand, the dummy frit 20 is provided at several positions on the main surface of the back substrate, and has a length of 5 to 15 mm (for example, about 10 mm), a width of 3 to 7 mm (for example, about 5 mm), and a thickness of 300 to 800 μm (for example, about 500 μm). There are 20 things on the outer edge almost evenly. The material of the dummy frit 20 may be the same as that of the glass frit 19, or may be a material having a softening point lower than that of the glass frit 19 or a material having a lower viscosity when softened. If it is the same material, there exists an advantage that a formation (application | coating) process becomes easy. If the material has a low softening point or a material having a low viscosity when softened, the distance between the front substrate 1 and the rear substrate 2 after sealing can be easily made substantially equal to the case without the dummy frit 20. . By using such a dummy frit 20, it is possible to increase the distance between the front substrate 1 and the rear substrate 2 immediately before the generation of plasma, the start of nitrogen gas blowing, and sealing, so that the gas replacement in the space between the substrates can be performed. Not only can it be performed more quickly, but also the substance derived from the altered layer, moisture, carbon dioxide and the like removed by the generation of plasma can be expelled from the space between the substrates to the outside.

  Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and those skilled in the art will readily understand that various modifications can be made.

  For example, after applying the glass frit, the frit may be temporarily fired before alignment. Alternatively, in the step of forming the phosphor layer, the phosphor layer can be simultaneously fired at the same time as the frit temporary firing without firing the phosphor layer.

  Moreover, although the case where one tip pipe | tube was used was illustrated, you may flow-exclude using two chip pipe | tubes. “Flow sealing / discharging” is a method of accelerating gas replacement in the panel by exhausting air from the other tip tube while blowing nitrogen or dry air from one tip tube during sealing. In this case, in the step of starting plasma generation or nitrogen gas blowing, one tip tube does nothing (closes the valve between the tip tube and the gas supply source) and supplies gas from the other tip tube. Alternatively, gas may be supplied from both tip tubes. When the gas is supplied from both the tip tubes, a PDP with less in-plane unevenness can be obtained.

  According to the production method of the present invention, a deteriorated layer that can be generated on the surface of the protective layer during the production of the PDP can be sufficiently removed, so that a PDP having an excellent panel life can be obtained.

A mode is schematically shown in which the first conductor plate and the second conductor plate are arranged outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate. Side view The side view which shows typically the aspect of the conductor board and board | substrate in Embodiment 1 of this invention The flowchart which shows schematic structure of the manufacturing process of PDP in Embodiment 1 of this invention. The expanded sectional view which shows typically the aspect of the conductor board and board | substrate in Embodiment 2 of this invention The top view which shows typically the formation arrangement of the frit in Embodiment 2 of this invention The perspective view which shows the schematic structure of PDP typically

Explanation of symbols

1 Front substrate (surface plate)
2 Back substrate (back plate)
3 First conductor plate 4 Second conductor plate 5 Clip member 6 Tip tube 7 Frit ring 8 Piping 9 Chuck head 10 High frequency power supply 11 Connector 12 Copper plate or copper wire 13 Base 14 Copper plate or copper wire 15 Insulating member (insulating plate)
16 Shield Case 17 Insulating Plate 18 Partition 19 Glass Frit 20 Dummy Frit 30 Front Substrate 31 First Glass Substrate 32a, 32b Display Electrode 33 First Dielectric Layer 34 Protective Layer 40 Back Substrate 41 Second Glass Substrate 42 Address Electrode 43 Second Dielectric layer 45 Partitions 46R, 46G, 46B Phosphor layer 50 Discharge space 51 Discharge cell 60 PDP

Claims (11)

A method for manufacturing a plasma display panel, comprising:
(I) A front substrate in which a first electrode, a first dielectric layer and a protective layer are formed on a first glass substrate, and a second electrode, a second dielectric layer, a partition and a phosphor layer on the second glass substrate. Preparing a back substrate on which is formed,
(Ii) applying a glass frit to the front substrate or the back substrate;
(Iii) a step of disposing the front substrate and the rear substrate so as to face each other so that the glass frit is positioned between the front substrate and the rear substrate;
(Iv) disposing the first conductor plate and the second conductor plate outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate;
(V) While supplying gas between the front substrate and the rear substrate through a through hole provided in at least one of the front substrate and the rear substrate, a voltage is applied between the first conductor plate and the second conductor plate. Applying and generating plasma between the front substrate and the back substrate,
(Vi) a step of melting the glass frit to seal the front substrate and the rear substrate; and (vii) after exhausting a gas existing between the front substrate and the rear substrate, between the front substrate and the rear substrate. A manufacturing method comprising the step of encapsulating a gas containing Xe.   The protective layer includes at least one layer, and each of the layers includes at least one selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide. The manufacturing method according to claim 1.   The manufacturing method according to claim 1, wherein a pulse voltage or a high frequency voltage is applied between the front substrate and the rear substrate in the step (v).   The said process (v) WHEREIN: A 1st conductor board is electrically connected to the power supply used in order to apply the said voltage, and a 2nd conductor board is earth | grounded, The any one of Claims 1-3 characterized by the above-mentioned. The manufacturing method of crab.   The manufacturing method according to claim 1, wherein in the step (v), a gas containing a rare gas is supplied between the front substrate and the rear substrate.   The manufacturing method according to claim 5, wherein the rare gas is helium gas.   In the step (vi), the front substrate and the rear substrate are heated while supplying a gas containing water vapor of 0 to 10 ppm between the front substrate and the rear substrate. The manufacturing method in any one.   The front substrate and the back substrate are heated while supplying a gas containing 0 to 10 ppm of carbon dioxide between the front substrate and the back substrate in the step (vi). The manufacturing method in any one of. An apparatus for manufacturing a plasma display panel,
A first conductor plate and a second conductor plate,
A holding device for holding the first conductor plate and the second conductor plate outside the front substrate and the rear substrate so that the first conductor plate is in contact with the front substrate and the second conductor plate is in contact with the rear substrate;
A gas supply device for supplying gas between the front substrate and the rear substrate through a through hole provided in at least one of the front substrate and the rear substrate, and between the first conductor plate and the second conductor plate A manufacturing apparatus comprising a power source for applying a voltage.   The manufacturing apparatus according to claim 9, wherein the power source is a pulse power source or a high-frequency power source.   11. The manufacturing apparatus according to claim 9, wherein the first conductor plate is electrically connected to the power source, and the second conductor plate is grounded.

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