JP4382148B2 - Plasma display panel - Google Patents

Description

  The present invention relates to a plasma display panel used for a display device or the like.

  Since plasma display panels (hereinafter referred to as PDP) can achieve high definition and large screen, 65-inch class televisions have been commercialized. In recent years, PDP has been applied to high-definition televisions having more than twice the number of scanning lines as compared with the conventional NTSC system, and PDP containing no lead component is required in consideration of environmental problems.

  A PDP basically includes a front plate and a back plate. The front plate is a glass substrate made of sodium borosilicate glass by a float method, a display electrode composed of a striped transparent electrode and a bus electrode formed on one main surface of the glass substrate, and a display electrode A dielectric layer that covers and acts as a capacitor, and a protective layer made of magnesium oxide (MgO) formed on the dielectric layer. On the other hand, the back plate includes a glass substrate, a stripe-shaped address electrode formed on one main surface of the glass substrate, a base dielectric layer covering the address electrode, and a partition formed on the base dielectric layer. , And phosphor layers that emit light in red, green, and blue colors formed between the barrier ribs.

  The front plate and the back plate are hermetically sealed with their electrode forming surfaces facing each other, and Ne—Xe discharge gas is sealed at a pressure of 400 Torr to 600 Torr in a discharge space partitioned by a partition wall. PDP discharges by selectively applying a video signal voltage to the display electrodes, and the ultraviolet rays generated by the discharge excite each color phosphor layer to emit red, green, and blue light, thereby realizing color image display is doing.

  Silver electrodes for ensuring conductivity are used for the bus electrodes of the display electrodes, and low-melting glass mainly composed of lead oxide is used for the dielectric layer. However, due to recent environmental concerns Examples in which the lead component is not included as the dielectric layer are disclosed (for example, see Patent Documents 1, 2, 3, and 4).

JP 2003-128430 A JP 2002-053342 A JP 2001-045877 A JP-A-9-050769

  In recent years, PDP has been increasingly applied to high-definition televisions having twice or more scanning lines as compared with the conventional NTSC system.

  As a result of such high-definition, the number of scanning lines increases, the number of display electrodes increases, and the display electrode interval decreases. Therefore, the diffusion of silver ions from the silver electrode constituting the display electrode to the dielectric layer and the glass substrate increases. When silver ions diffuse into the dielectric layer or the glass substrate, they are reduced by alkali metal ions in the dielectric layer or divalent tin ions contained in the glass substrate to form silver colloids. As a result, the dielectric layer and the glass substrate are strongly colored yellow or brown, and the silver oxide is subjected to a reducing action to generate oxygen and generate bubbles in the dielectric layer.

  Therefore, as the number of scanning lines increases, yellowing of the glass substrate and generation of bubbles in the dielectric layer become more prominent, which significantly deteriorates image quality and causes insulation failure of the dielectric layer.

  However, the example of a conventional dielectric layer that does not contain a lead component proposed in consideration of environmental problems cannot satisfy both the suppression of the yellowing phenomenon and the suppression of insulation failure of the dielectric layer. There was a problem.

  An object of the present invention is to solve such problems and to realize a PDP that secures high luminance and high reliability even in high-definition display and further considers environmental problems.

In order to achieve the above object, the PDP of the present invention has a front plate in which a display electrode, a dielectric layer and a protective layer are formed on a glass substrate, and an electrode, a partition and a phosphor layer on the substrate. The PDP has a discharge space formed by opposingly arranging the back plate and sealing the periphery, wherein the display electrode contains at least silver, and the dielectric layer substantially contains a lead component. And bismuth oxide, molybdenum oxide, calcium oxide, and barium oxide, and at least one of cerium oxide, manganese oxide, and tungsten oxide.

  According to such a configuration, it is possible to realize a PDP that is free from yellowing of the dielectric layer and does not deteriorate the withstand voltage performance, has a high visible light transmittance, and is excellent in environmentally friendly display quality.

Furthermore, the dielectric layer preferably contains 0.1% by weight or more and 7% by weight or less of molybdenum oxide and at least one of cerium oxide, manganese oxide, and tungsten oxide. For example, molybdenum oxide, or any one of cerium oxide, manganese oxide, and tungsten oxide can react with silver ions to suppress the formation of silver colloid, thereby preventing yellowing of the glass substrate and the dielectric layer. .

Furthermore, the zinc dielectric layer is oxide, boron oxide, silicon oxide, aluminum oxide, calcium oxide, it is desirable to include at least one of strontium oxide, and barium oxide, as the dielectric layer, yellowing and dielectric strength performance Thus, a PDP having a high visible light transmittance and excellent in environmentally friendly display quality can be realized.

  Furthermore, it is desirable to make the first dielectric layer thinner than the second dielectric layer, and yellowing and bubble generation can be suppressed, and a dielectric layer with high visible light transmittance can be obtained.

  As described above, according to the present invention, it is possible to realize a PDP that secures high luminance and high reliability even in high-definition display and further considers environmental problems.

The perspective view which shows the structure of PDP in embodiment of this invention Sectional drawing of the front plate showing the configuration of the dielectric layer of the PDP

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view showing the structure of a PDP according to an embodiment of the present invention. The basic structure of the PDP is the same as that of a general AC surface discharge type PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other, and its outer peripheral portion is sealed with a glass frit or the like. The material is hermetically sealed. The discharge space 16 inside the sealed PDP 1 is filled with a discharge gas such as Ne or Xe at a pressure of 400 Torr to 600 Torr.

  On the front glass substrate 3 of the front plate 2, a pair of strip-like display electrodes 6 made up of scanning electrodes 4 and sustain electrodes 5 and black stripes (light-shielding layers) 7 are arranged in a plurality of rows in parallel with each other. A dielectric layer 8 serving as a capacitor is formed on the front glass substrate 3 so as to cover the display electrode 6 and the light shielding layer 7, and a protective layer 9 made of magnesium oxide (MgO) is formed on the surface. Has been.

  On the back glass substrate 11 of the back plate 10, a plurality of strip-like address electrodes 12 are arranged in parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Layer 13 is covering. Further, a partition wall 14 having a predetermined height is formed on the base dielectric layer 13 between the address electrodes 12 to divide the discharge space 16. For each address electrode 12, a phosphor layer 15 that emits red, green, and blue light by ultraviolet rays is sequentially applied to the grooves between the barrier ribs 14 and formed. A discharge cell is formed at a position where the scan electrode 4 and the sustain electrode 5 intersect with the address electrode 12, and the discharge cell having the red, green and blue phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. Become a pixel.

FIG. 2 is a cross-sectional view of the front plate 2 showing the configuration of the dielectric layer 8 of the PDP in the embodiment of the present invention, which is shown upside down with respect to FIG. As shown in FIG. 2, a display electrode 6 and a light shielding layer 7 including scanning electrodes 4 and sustain electrodes 5 are formed in a pattern on a front glass substrate 3 manufactured by a float method or the like. Scan electrode 4 and sustain electrode 5 are made of transparent electrodes 4a and 5a made of indium tin oxide (ITO) or tin oxide (SnO ₂ ), respectively, and metal bus electrodes 4b and 5b formed on transparent electrodes 4a and 5a. It is comprised by. The metal bus electrodes 4b and 5b are used for the purpose of imparting conductivity in the longitudinal direction of the transparent electrodes 4a and 5a, and are formed of a conductive material whose main component is a silver (Ag) material.

  The dielectric layer 8 includes a first dielectric layer 81 provided on the front glass substrate 3 so as to cover the transparent electrodes 4a and 5a, the metal bus electrodes 4b and 5b, and the light shielding layer 7, and a first dielectric. The second dielectric layer 82 formed on the layer 81 has at least two layers, and the protective layer 9 is formed on the second dielectric layer 82.

  Next, a method for manufacturing a PDP will be described. First, the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 are formed on the front glass substrate 3. The transparent electrodes 4a and 5a and the metal bus electrodes 4b and 5b are formed by patterning using a photolithography method or the like. The transparent electrodes 4a and 5a are formed using a thin film process or the like, and the metal bus electrodes 4b and 5b are solidified by baking a paste containing a silver (Ag) material at a desired temperature. Similarly, the light shielding layer 7 is also formed by screen printing a paste containing a black pigment or by forming a black pigment on the entire surface of the glass substrate and then patterning and baking using a photolithography method.

  Next, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7, thereby forming a dielectric paste layer (dielectric material layer). After the dielectric paste is applied, the surface of the applied dielectric paste is leveled by leaving it to stand for a predetermined time, so that a flat surface is obtained. Thereafter, the dielectric paste layer is baked and solidified to form the dielectric layer 8 that covers the scan electrode 4, the sustain electrode 5, and the light shielding layer 7. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent. Next, a protective layer 9 made of magnesium oxide (MgO) is formed on the dielectric layer 8 by a vacuum deposition method. Through the above steps, predetermined components (scanning electrode 4, sustaining electrode 5, light shielding layer 7, dielectric layer 8, and protective layer 9) are formed on front glass substrate 3, and front plate 2 is completed.

  On the other hand, the back plate 10 is formed as follows. First, the structure for the address electrode 12 is formed by a method of screen printing a paste containing silver (Ag) material on the rear glass substrate 11 or a method of patterning using a photolithography method after forming a metal film on the entire surface. An address electrode 12 is formed by forming a material layer to be an object and firing it at a desired temperature. Next, a dielectric paste is applied on the rear glass substrate 11 on which the address electrodes 12 are formed by a die coating method so as to cover the address electrodes 12 to form a dielectric paste layer. Thereafter, the base dielectric layer 13 is formed by firing the dielectric paste layer. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent.

  Next, a partition wall forming paste including a partition wall material is applied on the base dielectric layer 13 and patterned into a predetermined shape to form a partition wall material layer and then fired to form the partition walls 14. Here, as a method of patterning the partition wall paste applied on the base dielectric layer 13, a photolithography method or a sand blast method can be used. Next, the phosphor layer 15 is formed by applying a phosphor paste containing a phosphor material on the base dielectric layer 13 between the adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14 and baking it. Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

  In this way, the front plate 2 and the back plate 10 having predetermined constituent members are arranged to face each other so that the scanning electrodes 4 and the address electrodes 12 are orthogonal to each other, and the periphery thereof is sealed with a glass frit, so that the discharge space 16 is filled with a discharge gas containing Ne, Xe or the like, thereby completing the PDP 1.

The first dielectric layer 81 and the second dielectric layer 82 constituting the dielectric layer 8 of the front plate 2 will be described in detail. The dielectric material of the first dielectric layer 81 is composed of the following material composition. That is, it contains 20% to 40% by weight of bismuth oxide (Bi ₂ O ₃ ) and 0.5% to 15% by weight of calcium oxide (CaO), and further includes molybdenum oxide (MoO ₃ ) and tungsten oxide ( WO _3), cerium oxide (CeO _2), it contains at least one kind of 0.1 wt% to 7 wt% selected from manganese oxide (MnO _2).

  Furthermore, it contains 0.5 wt% to 12 wt% of at least one selected from strontium oxide (SrO) and barium oxide (BaO).

In place of molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ), copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), cobalt oxide At least one selected from (Co ₂ O ₃ ), vanadium oxide (V ₂ O ₇ ), and antimony oxide (Sb ₂ O ₃ ) may be contained in an amount of 0.1 wt% to 7 wt%.

Further, as components other than the above, zinc oxide (ZnO) is 0 wt% to 40 wt%, boron oxide (B ₂ O ₃ ) is 0 wt% to 35 wt%, and silicon oxide (SiO ₂ ) is 0 wt% to A material composition that does not include a lead component, such as 15% by weight and aluminum oxide (Al ₂ O ₃ ), such as 0% by weight to 10% by weight, may be included, and the content of these material compositions is not particularly limited, It is the content range of the material composition of the prior art level.

  A dielectric material powder is produced by pulverizing a dielectric material composed of these composition components with a wet jet mill or a ball mill so that the average particle size is 0.5 μm to 2.5 μm. Next, 55 wt% to 70 wt% of the dielectric material powder and 30 wt% to 45 wt% of the binder component are well kneaded with three rolls to obtain a first dielectric layer paste for die coating or printing. Make it.

  The binder component is ethyl cellulose, terpineol containing 1% to 20% by weight of acrylic resin, or butyl carbitol acetate. In the paste, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, and tributyl phosphate are added as plasticizers as needed, and glycerol monooleate, sorbitan sesquioleate, and homogenol (Kao Corporation) as dispersants. The printability may be improved by adding a phosphoric ester of an alkyl allyl group or the like.

  Next, using this first dielectric layer paste, the front glass substrate 3 is printed by a die coating method or a screen printing method so as to cover the display electrode 6 and dried, and then slightly less than the softening point of the dielectric material. Bake at a high temperature of 575 ° C to 590 ° C.

Next, the second dielectric layer 82 will be described. The dielectric material of the second dielectric layer 82 is composed of the following material composition. That is, it contains 11 to 40% by weight of bismuth oxide (Bi ₂ O ₃ ) and 6 to 28% by weight of barium oxide (BaO), and further contains molybdenum oxide (MoO ₃ ) and tungsten oxide (WO ₃ ). , Cerium oxide (CeO ₂ ), manganese oxide (MnO ₂ ) at least one selected from 0.1 wt% to 7 wt%.

  Furthermore, it contains 0.8 wt% to 17 wt% of at least one selected from calcium oxide (CaO) and strontium oxide (SrO).

In place of molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ), copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), cobalt oxide At least one selected from (Co ₂ O ₃ ), vanadium oxide (V ₂ O ₇ ), and antimony oxide (Sb ₂ O ₃ ) may be contained in an amount of 0.1 wt% to 7 wt%.

Further, as components other than the above, zinc oxide (ZnO) is 0 wt% to 40 wt%, boron oxide (B ₂ O ₃ ) is 0 wt% to 35 wt%, and silicon oxide (SiO ₂ ) is 0 wt% to A material composition that does not include a lead component, such as 15% by weight and aluminum oxide (Al ₂ O ₃ ), such as 0% by weight to 10% by weight, may be included, and the content of these material compositions is not particularly limited, It is the content range of the material composition of the prior art level.

  A dielectric material powder is produced by pulverizing a dielectric material composed of these composition components with a wet jet mill or a ball mill so that the average particle size is 0.5 μm to 2.5 μm. Next, 55 wt% to 70 wt% of the dielectric material powder and 30 wt% to 45 wt% of the binder component are well kneaded with three rolls to obtain a second dielectric layer paste for die coating or printing. Make it. The binder component is ethyl cellulose, terpineol containing 1% to 20% by weight of acrylic resin, or butyl carbitol acetate. In the paste, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, and tributyl phosphate are added as plasticizers as needed, and glycerol monooleate, sorbitan sesquioleate, and homogenol (Kao Corporation) as dispersants. The printability may be improved by adding a phosphoric ester of an alkyl allyl group or the like.

  Next, using this second dielectric layer paste, printing is performed on the first dielectric layer 81 by screen printing or die coating, followed by drying. Thereafter, the temperature is 550 ° C., which is slightly higher than the softening point of the dielectric material. Bake at ~ 590 ° C.

  Since the effect of improving the panel brightness and reducing the discharge voltage becomes more significant as the thickness of the dielectric layer 8 is smaller, it is desirable to set the thickness as small as possible within the range where the withstand voltage does not decrease. . From the viewpoint of such conditions and visible light transmittance, in the embodiment of the present invention, the film thickness of the dielectric layer 8 is set to 41 μm or less, the first dielectric layer 81 is 5 μm to 15 μm, and the second dielectric The layer 82 is 20 μm to 36 μm.

Further, when the bismuth oxide (Bi ₂ O ₃ ) is 11 wt% or less in the second dielectric layer 82, coloring is less likely to occur, but bubbles are easily generated in the second dielectric layer 82, which is not preferable. On the other hand, if it exceeds 40% by weight, coloring tends to occur, which is not preferable for the purpose of increasing the transmittance.

Furthermore, it is necessary that there is a difference in the content of bismuth oxide (Bi ₂ O ₃ ) between the first dielectric layer 81 and the second dielectric layer 82. This is because, when the contents of bismuth oxide (Bi ₂ O ₃ ) in the first dielectric layer 81 and the second dielectric layer 82 are the same, the first dielectric layer 81 is affected by bubbles generated in the first dielectric layer 81. This is because a phenomenon that bubbles are also generated in the second dielectric layer 82 in the firing process of the two dielectric layers 82 has been confirmed.

Then, than the content of bismuth oxide (Bi ₂ O ₃₎ in first dielectric layer 81, when the content of bismuth oxide (Bi ₂ O ₃₎ in second dielectric layer 82 is small, the dielectric layer 8 Since the second dielectric layer 82 occupies approximately 50% or more of the total film thickness, in addition to the above-described effects, it is difficult to produce a metallic color, the transmittance can be increased, and Bi-based materials are expensive. Therefore, the cost of the raw material to be used can be reduced.

Moreover, than the content of bismuth oxide (Bi ₂ O ₃₎ in first dielectric layer 81, when the content of bismuth oxide (Bi ₂ O ₃₎ in second dielectric layer 82 is large, the second dielectric layer Since the softening point of 82 can be lowered, removal of bubbles during the firing process can be promoted.

  The PDP manufactured in this manner has little coloring phenomenon (yellowing) of the front glass substrate 3 even when a silver (Ag) material is used for the display electrode 6, and bubbles are generated in the dielectric layer 8. It has been confirmed that the dielectric layer 8 excellent in withstand voltage performance is realized.

Next, in the PDP according to the embodiment of the present invention, the reason why yellowing and generation of bubbles in the first dielectric layer 81 are suppressed by these dielectric materials will be considered. That is, by adding molybdenum oxide (MoO ₃ ) or tungsten oxide (WO ₃ ) to dielectric glass containing bismuth oxide (Bi ₂ O ₃ ), Ag ₂ MoO ₄ , Ag ₂ Mo ₂ O ₇ , Ag ₂ are added. It is known that compounds such as Mo ₄ O ₁₃ , Ag ₂ WO ₄ , Ag ₂ W ₂ O ₇ , and Ag ₂ W ₄ O ₁₃ are easily formed at a low temperature of 580 ° C. or lower. In the embodiment of the present invention, since the firing temperature of the dielectric layer 8 is 550 ° C. to 590 ° C., silver ions (Ag ⁺ ) diffused into the dielectric layer 8 during firing are contained in the dielectric layer 8. It reacts with molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ) to produce and stabilize a stable compound. That is, since silver ions (Ag ⁺ ) are stabilized without being reduced, they do not aggregate to form a colloid. Therefore, the stabilization of silver ions (Ag ⁺ ) reduces the generation of oxygen accompanying the colloidalization of silver (Ag), thereby reducing the generation of bubbles in the dielectric layer 8.

On the other hand, in order to make these effects effective, in a dielectric glass containing bismuth oxide (Bi ₂ O ₃ ), molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), oxidation The content of manganese (MnO ₂ ) is preferably 0.1% by weight or more, more preferably 0.1% by weight or more and 7% by weight or less. In particular, if it is less than 0.1% by weight, the effect of suppressing yellowing is small, and if it exceeds 7% by weight, the glass is colored, which is not preferable.

  Further, by including calcium oxide (CaO) in the first dielectric layer 81, the calcium oxide (CaO) acts as an oxidant during the firing process of the first dielectric layer 81, and the binder remaining in the display electrode 6 is retained. There is an effect of promoting the removal of components. On the other hand, the inclusion of barium oxide (BaO) in the second dielectric layer 82 has the effect of increasing the transmittance of the second dielectric layer 82.

  That is, the dielectric layer 8 of the PDP in the embodiment of the present invention suppresses the yellowing phenomenon and the generation of bubbles in the first dielectric layer 81 in contact with the metal bus electrodes 4b and 5b made of silver (Ag) material. High light transmittance is realized by the second dielectric layer 82 provided on the first dielectric layer 81. As a result, it is possible to realize a PDP having a high transmittance with very few bubbles and yellowing as the entire dielectric layer 8.

(Example)
As the PDP in the embodiment of the present invention, the height of the barrier ribs is 0.15 mm, the interval between the barrier ribs (cell pitch) is 0.15 mm, and the display electrode is used so as to be compatible with a 42-inch high-definition television as a discharge cell. A PDP in which a Ne—Xe-based mixed gas having an Xe content of 15% by volume and an enclosure pressure of 60 kPa was produced at an interelectrode distance of 0.06 mm was evaluated.

A first dielectric layer and a second dielectric layer having the material composition shown in (Table 1) and (Table 2) were produced, and a PDP having the conditions shown in (Table 3) was produced by combining these dielectric layers. . In Table 3, panel numbers 1 to 26 are shown as examples of the PDP in the embodiment of the present invention, and panel numbers 27 to 30 are shown as comparative examples. In addition, the sample Nos. Of the material compositions in (Table 1) and (Table 2). A12, A13, B11, and B12 are also comparative examples with the present invention. In addition, “other material composition” which is the item of the material composition shown in (Table 1) and (Table 2) is, as described above, zinc oxide (ZnO), boron oxide (B ₂ O ₃ ), oxidation It is a material composition that does not contain lead components, such as silicon (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), etc. The content of these material compositions is not particularly limited, and is within the range of the material composition level of the conventional technology .

As shown in (Table 1) to (Table 3), the PDPs having the panel numbers 1 to 26 have 20 weight of bismuth oxide (Bi ₂ O ₃ ) on the metal bus electrodes 4b and 5b made of silver (Ag) material. % To 40% by weight, 0.5% to 15% by weight of calcium oxide (CaO), molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), manganese oxide (MnO ₂₎ And at least one selected from strontium oxide (SrO) and barium oxide (BaO) at 0.5% to 12% by weight. It is covered with a first dielectric layer 81 baked at 560 ° C. to 590 ° C. using body glass, and the film thickness is set to 5 μm to 15 μm.

Further, on the first dielectric layer 81, at least bismuth oxide (Bi ₂ O ₃ ) is 11 wt% to 40 wt%, barium oxide (BaO) is 6 wt% to 28 wt%, and molybdenum oxide (MoO). ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), manganese oxide (MnO ₂ ) at least one selected from 0.1 wt% to 7 wt%, calcium oxide (CaO), strontium oxide ( The second dielectric layer is baked at 550 ° C. to 570 ° C. using a dielectric glass containing 0.8% by weight to 17% by weight of at least one selected from SrO) so as to have a thickness of 20 μm to 35 μm. 82 is formed.

The PDPs having the panel numbers 27 and 28 have a case where the content of bismuth oxide (Bi ₂ O ₃ ) in the dielectric glass constituting the first dielectric layer 81 shown in Table 1 is small, and molybdenum oxide ( The results are obtained when none of MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ) is contained. and when the content of bismuth oxide in the dielectric glass constituting the layers 82 (Bi ₂ O ₃₎ is the same as the content of bismuth oxide in the first dielectric layer 81 (Bi ₂ O _3), molybdenum oxide ( This is a result when none of MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ) is contained.

  The PDPs having panel numbers 1 to 30 were prepared and evaluated for the following items, and the evaluation results are shown in (Table 3). First, the transmittance of the front plate 2 was measured using a spectrometer. The measurement was obtained as the actual transmittance of the dielectric layer 8 by subtracting the transmittance of the front glass substrate 3 and the influence of the electrodes, and the results are shown in Table 3.

Moreover, the degree of yellowing by silver (Ag) was measured with a color meter (Minolta strain; CR-300), and the b ^* value indicating the degree of yellow was measured. In addition, the standard of b ^* value that yellowing affects the display performance of PDP is b ^* = 3. The larger this value, the more yellowing is noticeable and the color temperature is lowered as PDP, which is not preferable.

  Furthermore, 20 PDPs with panel numbers 1 to 30 were produced and subjected to an accelerated life test. The accelerated life test was performed by continuously discharging for 4 hours at a discharge sustaining voltage of 200 V and a frequency of 50 kHz. Thereafter, the number of PDPs whose dielectric layers were destroyed (insulation breakdown defects) was evaluated. Since dielectric breakdown defects are caused by defects such as bubbles generated in the dielectric layer 8, it is considered that a panel in which dielectric breakdown has occurred has many bubbles in the dielectric layer 8.

  From the results of (Table 3), in the PDP having panel numbers 1 to 26 corresponding to the PDP in the embodiment of the present invention, yellowing due to silver (Ag) and generation of bubbles are suppressed, and visible light transmission of the dielectric layer is achieved. The rate is as high as 86% to 91%, and the b * value related to yellowing is as low as 1.7 to 2.8, indicating that there is no dielectric breakdown after the accelerated life test.

On the other hand, in the PDP having the panel number 27, which contains as little as 15% by weight of bismuth oxide (Bi ₂ O ₃ ) in the dielectric glass of the first dielectric layer and does not contain calcium oxide (CaO), yellowing occurs. The b * value indicating the degree is as small as 2.1, but because the dielectric glass has low fluidity, the adhesion between the display electrode and the front glass substrate deteriorates, and in particular, bubbles are generated at the interface and accelerated. Increases dielectric breakdown after life test. In panel number 28 in which the dielectric glass of the first dielectric layer does not contain molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), or manganese oxide (MnO ₂ ), yellow The degree of change is large, resulting in increased bubble generation and dielectric breakdown.

In addition, in the dielectric glass of the second dielectric layer, the content of bismuth oxide (Bi ₂ O ₃ ) is the same as that of the first dielectric layer, and the panel number 29 that does not contain barium oxide (BaO) is visible. As the light transmittance decreases, the number of bubbles in the dielectric layer increases. On the other hand, the content of bismuth oxide (Bi ₂ O ₃ ) in the dielectric glass of the second dielectric layer is reduced, molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), oxidation In the panel number 30 containing no manganese (MnO ₂ ), the visible light transmittance is good, but the flowability of the glass is poor, so that many bubbles are generated and the dielectric breakdown is remarkably increased.

In the above description, molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ) are used for the dielectric glass of the first dielectric layer and the second dielectric layer. Although the structure containing at least one of them has been described, instead of these, copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), cobalt oxide (Co ₂ O ₃ ), vanadium oxide (V ₂ O ₇₎ ) And at least one selected from antimony oxide (Sb ₂ O ₃ ) is also effective.

  In addition, the numerical value of the content of each material composition described above has a measurement error of about ± 0.5% by weight in the dielectric material, and a measurement error of about ± 2% by weight in the dielectric layer after firing. To do. The same effects as those of the present invention can be obtained even in a material composition with a content in a numerical range including these errors.

  As described above, according to the PDP in the embodiment of the present invention, it is possible to realize an environment-friendly PDP having a high visible light transmittance as a dielectric layer, a high withstand voltage performance, and further containing no lead component. it can.

  As described above, the PDP according to the present invention does not cause yellowing of dielectric layers or deterioration of dielectric strength performance, and is useful for a large-screen display device by realizing an environment-friendly PDP having excellent display quality. .

1 PDP
2 Front plate 3 Front glass substrate 4 Scan electrode 4a, 5a Transparent electrode 4b, 5b Metal bus electrode 5 Sustain electrode 6 Display electrode 7 Black stripe (light shielding layer)
8 Dielectric layer 9 Protective layer 10 Back plate 11 Back glass substrate 12 Address electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space 81 First dielectric layer 82 Second dielectric layer

Claims (3)

A front plate having a display electrode, a dielectric layer and a protective layer formed on a glass substrate and a back plate having an electrode, a partition and a phosphor layer formed on the substrate are arranged opposite to each other and sealed around the periphery. A plasma display panel in which a discharge space is formed, wherein the display electrode contains at least silver, and the dielectric layer substantially does not contain a lead component, and bismuth oxide, molybdenum oxide, calcium oxide And a barium oxide, and at least one of cerium oxide, manganese oxide, and tungsten oxide. 2. The dielectric layer according to claim 1, wherein the dielectric layer contains 0.1 wt% or more and 7 wt% or less of molybdenum oxide and at least one of cerium oxide, manganese oxide, and tungsten oxide. Plasma display panel. The dielectric layer according to claim 1 or 2, wherein the dielectric layer includes at least one of zinc oxide, boron oxide, silicon oxide, aluminum oxide, calcium oxide, strontium oxide, and barium oxide. Plasma display panel.

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