JP2004363010A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly efficient plasma display panel wherein an interference between discharge cells is suppressed by precisely forming a cubic structure such as a recessed part on the surface of a dielectric layer. <P>SOLUTION: This plasma display panel has the dielectric layer 27 formed by baking a dielectric material at a lower temperature than its softening point temperature, and the dielectric layer has at least one recessed part 27a for every discharge cell 35 on its discharge space 34 side surface. Thereby, discharge is formed so as to be concentrated on the bottom surface of the recessed part 27a where the film thickness of the dielectric layer 27 is thin, and high efficiency can be materialized. In addition, when forming the dielectric layer 27, the dielectric material is baked at the lower temperature than the its softening point temperature, deformation such as a sharp pointed swelling caused by shrinkage during baking, which becomes a cause for leakage of charged particles between discharge cells 35, is restrained from occurring at the end parts such as corners and sides of the recessed part 27a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma display panel known as a display device.
[0002]
[Prior art]
In recent years, expectations for large-screen, wall-mounted televisions as interactive information terminals have been increasing. There are many display devices for this purpose, such as a liquid crystal display panel, a field emission display, and an electroluminescence display, some of which are commercially available and some of which are under development. Among these display devices, a plasma display panel (PDP) has attracted attention as a thin display device with excellent visibility because it is a self-luminous type, can display a beautiful image, and is easy to enlarge the screen. Resolution and large screen are being promoted.
[0003]
This PDP is roughly classified into two types: an AC type and a DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type. At present, PDPs of the AC type and the surface discharge type have become the mainstream.
[0004]
FIG. 9 shows an example of a panel structure of the PDP. As shown in FIG. 9, the PDP includes a front panel 1 and a rear panel 2.
[0005]
The front panel 1 is formed by arranging a plurality of pairs of stripe-shaped display electrodes 6 formed by scanning electrodes 4 and sustain electrodes 5 on an insulating and transparent front substrate 3 such as a glass substrate. A dielectric layer 7 is formed so as to cover the display electrode 6 group, and a protective layer 8 made of MgO is formed on the dielectric layer 7. The scanning electrode 4 and the sustaining electrode 5 are respectively composed of transparent electrodes 4a, 5a and bus electrodes 4b, 5b made of Cr / Cu / Cr or Ag electrically connected to the transparent electrodes 4a, 5a. ing. Although not shown, a plurality of black stripes are formed between the display electrodes 6 as light shielding films in parallel with the display electrodes 6.
[0006]
The rear panel 2 has an address electrode 10 formed in a direction orthogonal to the display electrode 6 on a rear substrate 9 disposed opposite to the front substrate 3 so as to cover the address electrode 10. A dielectric layer 11 is formed, and a plurality of stripe-shaped partitions 12 are formed on the dielectric layer 11 between the address electrodes 10 in parallel with the address electrodes 10. Phosphor layers 13R, 13G, and 13B of three colors of red, green, and blue are formed on the surface.
[0007]
The front panel 1 and the rear panel 2 are disposed so as to face each other so that the display electrodes 6 and the address electrodes 10 are orthogonal to each other and form a minute discharge space 14 with the partition wall 12 interposed therebetween. A PDP is formed by sealing with a member (not shown) and enclosing a discharge gas obtained by mixing neon and xenon or the like in the discharge space at a pressure of about 66500 Pa (500 Torr).
[0008]
The discharge space 14 is partitioned into a plurality of partitions by partition walls 12. The display electrodes 6 are provided between the partition walls 12 so as to form a plurality of discharge cells 15 serving as light emitting pixel regions. The electrodes 10 are arranged so as to be orthogonal.
[0009]
That is, as shown in FIG. 10, the display electrode 6 is formed by arranging the scan electrode 4 and the sustain electrode 5 with the discharge gap 16 interposed therebetween, and the region surrounded by the display electrode 6 and the partition 12 emits light. The discharge cells 15 are pixel areas, and the non-light emitting areas 17 are between the display electrodes 6 of the adjacent discharge cells 15.
[0010]
In this PDP, a discharge is generated by a periodic voltage applied to the address electrode 12 and the display electrode 6, and ultraviolet rays generated by the discharge are applied to the phosphor layers 13R, 13G, and 13B to be converted into visible light. Perform image display.
[0011]
For the development of this PDP, higher luminance, higher efficiency, lower power consumption, and lower cost are indispensable. As one of the techniques for achieving high efficiency, for example, as described in Patent Document 1, a technique of forming a three-dimensional structure such as a concave portion on the surface of the dielectric layer 7 is known. .
[0012]
[Patent Document 1]
JP-A-8-250029
[0013]
[Problems to be solved by the invention]
When a three-dimensional structure such as a concave portion is formed on the surface of the dielectric layer 7, a method of applying a dielectric material as a precursor of the dielectric layer 7 so as to have a concave shape, and then firing the material is adopted. Can be Here, the dielectric layer 7 is required to take out the emitted light from the phosphor layers 13R, 13G, and 13B without blocking in order to increase the efficiency, and therefore, the transmittance of the dielectric layer 7 is required to be high. Is required. Therefore, in general, the firing temperature of the dielectric material is set to a temperature several tens of degrees higher than its softening point in order to maintain the transmittance as high as possible by promoting the sintering of the dielectric material. Often set. For example, the firing temperature is set to 590 ° C. for a dielectric material having a softening point of 580 ° C., and the transmittance including the substrate 3 in that case is about 70%.
[0014]
Here, when the dielectric material is fired at a temperature higher than the softening point temperature, it temporarily softens and then solidifies, and at this time, the dielectric layer 7 contracts. In the concave portion formed on the surface of the layer 7, there may be a problem that the shape of the concave portion is raised so that the edge portion such as the corner portion or the side portion is pointed and the shape is deformed. When such a bulge exists on the surface of the dielectric layer 7, when the front panel 1 and the rear panel 2 are opposed to each other with the partition 12 interposed therebetween, if the bulge is a portion that contacts the partition 12, This causes a gap between the second partition 2 and the partition 12. If such a gap is present, leakage of charged particles or the like may occur through the gap, causing interference between the discharges between the discharge cells 15 and adversely affecting the display characteristics of the PDP image.
[0015]
The present invention has been made in order to solve such a problem, and by forming a three-dimensional structure such as a concave portion on the surface of a dielectric layer with high precision, interference between discharge cells is suppressed, and the efficiency is high. It is intended to realize a plasma display panel.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, a plasma display panel according to the present invention comprises a pair of front and rear substrates disposed opposite to each other so as to form a discharge space partitioned by a partition between the substrates, and discharge between the partition. A plurality of display electrodes arranged and arranged on the front substrate so that cells are formed, and formed on the front substrate so as to cover the display electrodes, and at least for each discharge cell on the surface on the discharge space side A dielectric layer having one concave portion, and a phosphor layer that emits light by discharge between the display electrodes, wherein the dielectric layer is formed by firing a dielectric material at a temperature lower than its softening point. It is characterized by the following.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
That is, the invention according to claim 1 of the present invention comprises a pair of front and rear substrates disposed opposite to each other so as to form a discharge space partitioned by a partition between the substrates, and a discharge cell between the partition. Are formed on the front substrate so as to cover the display electrodes, and a plurality of display electrodes are formed on the front substrate so as to cover the display electrodes. A dielectric layer having two concave portions, and a phosphor layer emitting light by discharge between the display electrodes, wherein the dielectric layer is formed by firing a dielectric material at a temperature lower than its softening point. A plasma display panel characterized by the following.
[0018]
According to a second aspect of the present invention, in the first aspect, the dielectric layer having the concave portion has a multilayer structure, and at least the uppermost dielectric layer of each of the layers constituting the dielectric layer is a dielectric layer. It is characterized in that the body material is formed by firing at a temperature lower than its softening point temperature.
[0019]
According to a third aspect of the present invention, in the second aspect, each of the layers constituting the dielectric layer is formed by firing the dielectric material at a temperature lower than the softening point temperature of the dielectric layer below the layer. It is characterized by being formed by.
[0020]
According to a fourth aspect of the present invention, in the second aspect of the present invention, the concave portion is formed by hollowing out the upper dielectric layer so that the bottom surface is the surface of the dielectric layer formed on the lower layer side. It is characterized by having been formed.
[0021]
The invention according to claim 5 is the invention according to any one of claims 1 to 3, wherein the temperature lower than the softening point temperature is a temperature whose lower limit is 50 ° C lower than the softening point temperature. It is assumed that.
[0022]
The invention according to claim 6 is the invention according to any one of claims 1 to 4, wherein the dielectric layer contains a filler.
[0023]
The invention according to claim 7 is the invention according to claim 6, wherein the filler has a refractive index of 1 to 2.
[0024]
The invention according to claim 8 is the invention according to any one of claims 1 to 4 and 6, wherein the dielectric layer is made of ZnO-B ₂ O ₃ -SiO ₂ System mixture, PbO-B ₂ O ₃ -SiO ₂ System mixture, PbO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ System mixture, PbO-ZnO-B ₂ O ₃ -SiO ₂ System mixture, Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ It is formed of a dielectric material containing a glass powder selected from a system mixture.
[0025]
Hereinafter, some examples of the plasma display panel according to the embodiments of the present invention will be described with reference to the drawings.
[0026]
FIG. 1 shows an example of the structure of a plasma display panel (PDP) according to an embodiment of the present invention. As shown in FIG. 1, the PDP includes a front panel 21 and a back panel 22.
[0027]
The front panel 21 is formed in a stripe shape in which a scanning electrode 24 and a sustain electrode 25 are paired on a transparent and insulating front substrate 23 such as a glass substrate made of a sodium borosilicate glass or the like by a float method. A plurality of display electrodes 26 arranged in pairs, a dielectric layer 27 is formed so as to cover the display electrodes 26, and a protective layer 28 made of MgO is formed on the dielectric layer 27. are doing. The scanning electrode 24 and the sustaining electrode 25 are respectively composed of transparent electrodes 24a and 25a, and bus electrodes 24b and 25b made of Cr / Cu / Cr or Ag electrically connected to the transparent electrodes 24a and 25a. It consists of. Although not shown, a plurality of black stripes are formed between the display electrodes 26 in parallel with the display electrodes 26 as black stripes as light-shielding films.
[0028]
The rear panel 22 has an address electrode 30 formed in a direction orthogonal to the display electrode 26 on a rear substrate 29 which is arranged to face the front substrate 23 so as to cover the address electrode 30. A dielectric layer 31 is formed, and a plurality of stripe-shaped partitions 32 are formed on the dielectric layer 31 between the address electrodes 30 in parallel with the address electrodes 30. Phosphor layers 33R, 33G, and 33B of three colors of red, green, and blue are formed on the surface.
[0029]
The front panel 21 and the rear panel 22 are arranged facing each other so that the display electrode 26 and the address electrode 30 are orthogonal to each other and form a minute discharge space 34 with the partition wall 32 interposed therebetween. A PDP is formed by sealing with a sealing member (not shown), and sealing the discharge space 34 with a discharge gas obtained by mixing neon and xenon at a pressure of about 66500 Pa (500 Torr).
[0030]
The discharge space 34 is partitioned into a plurality of partitions by partition walls 32. The display electrodes 26 are provided between the partition walls 32 so as to form a plurality of discharge cells 35 serving as luminescent pixel regions. 30 are arranged orthogonally.
[0031]
FIG. 2 is an enlarged view of the discharge cell 35 (FIG. 1) of the front panel 21. As shown in the figure, a dielectric layer 27 is formed on the front substrate 23 so as to cover the display electrode 26, and a discharge cell 35 (FIG. 1) is formed on the surface, that is, the discharge space 34 (FIG. 1). ) Has at least one recess 27a. The dielectric layer 27 is formed by firing a dielectric material at a temperature lower than its softening point.
[0032]
Next, a method of manufacturing a PDP according to an embodiment of the present invention will be described.
[0033]
First, on the substrate 23 on the front side of the front panel 21, ITO or SnO ₂ A transparent electrode material film made of the above is uniformly formed by a sputtering method. Next, a positive resist containing a novolak resin as a main component is applied on the transparent electrode material film, and the resist is cured by exposing it to ultraviolet rays through an exposure dry plate having a desired pattern. Next, development is performed with an alkaline aqueous solution to form a resist pattern. Thereafter, the substrate is immersed in a solution containing hydrochloric acid as a main component to perform etching, unnecessary portions are removed, and finally, the resist is peeled to form transparent electrodes 24a and 25a.
[0034]
Next, RuO ₂ Black frit, glass frit (PbO-B ₂ O ₃ -SiO ₂ System and Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ ), A conductive material such as Ag, and a glass frit (PbO-B ₂ O ₃ -SiO ₂ System and Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ And an electrode material film comprising a metal electrode material film containing the same, and irradiating ultraviolet rays through an exposure dry plate having a desired pattern to cure the exposed portions, and thereafter, an alkaline developer (0.3 wt% of A pattern is formed by developing using an aqueous solution of sodium carbonate), and then firing is performed at a temperature equal to or higher than the softening point of the glass frit, thereby forming the bus electrodes 24b and 25b on the transparent electrodes 24a and 25a. As described above, the display electrodes 26 of the front panel 21 can be formed.
[0035]
Next, a dielectric material of a paste-like glass powder-containing composition containing a glass powder, a binder resin, and a solvent is applied to the surface of the substrate 23 on which the display electrodes 26 are formed by, for example, a die coating method, and dried. Then, by firing, the dielectric layer 27 is formed. Here, the surface of the dielectric layer 27 is formed so as to have at least one concave portion 27a for each discharge cell 35. In the formation, the temperature at which the dielectric material is fired is lower than the softening point temperature of the dielectric material. Low temperature.
[0036]
Here, the formation of the concave portion 27a can be performed, for example, by a method such as half etching by a photolithography method.
[0037]
In addition, as a method of applying a dielectric material, which is a glass paste composition, to the surface of the substrate 23, the dielectric material is applied on a support film and dried to obtain a sheet-like dielectric material, which is transferred to the substrate. 23 may be used. In this case, the dielectric layer 27 is heated from the support film side while peeling off the cover film of the sheet-like dielectric material and then superposing the sheet-like dielectric material so that the surface of the dielectric material layer is in contact with the substrate 23. It is fixed to the substrate 23 by pressing with a roller. Thereafter, the support film is peeled off from the dielectric material layer fixed on the substrate 23, and then fired at a temperature lower than the softening point temperature, whereby the dielectric layer 27 is obtained. As a means used for the pressure bonding at this time, a simple roller that does not heat may be used in addition to the heating roller.
[0038]
Thereafter, a protective layer 28 is formed by uniformly forming a film of MgO on the dielectric layer 27 by an electron beam evaporation method. Thus, the front panel 21 of the PDP is obtained.
[0039]
On the other hand, in the method of manufacturing the rear panel 22 of the PDP, first, an address electrode 30 is formed on a substrate 29 on the rear side of the rear panel 22 manufactured by the float method in the same manner as the bus electrodes 24a and 25a on the front panel 21. I do. A dielectric layer 28 is formed thereon. This is also basically the same as the dielectric layer 27 of the front panel 21, but it is not necessary to set the firing temperature at the time of formation to be lower than the softening point temperature. Then, the partition 32 is formed on the dielectric layer 31.
[0040]
The material used for forming the partition 32 is a dielectric material that is a paste-like glass powder-containing composition containing glass powder, a binder resin, and a solvent. In addition, as a formation method, it can be formed using a photolithography method or a sandblast method.
[0041]
Next, phosphor materials corresponding to R, G, and B are applied between the partitions 32 and fired to form phosphor layers 33R, 33G, and 33B. Thus, the back panel 22 can be obtained.
[0042]
The front panel 21 and the rear panel 22 manufactured as described above are aligned and opposed to each other so that the display electrode 26 and the address electrode 30 intersect at a substantially right angle. Then, impurity gas is removed by exhausting the inside of the discharge space 34 partitioned by the partition walls 32, and the discharge gas 34 such as Ne, Xe, etc. By encapsulating and sealing the PDP, a PDP having a configuration as shown in FIG. 1 can be manufactured.
[0043]
Here, as one method for achieving high efficiency of the PDP, discharge is performed to a portion where light emission is blocked, that is, a region of the bus electrodes 24b and 25b having a low transmittance because of being formed of a metal material. It is effective to control the discharge so as not to spread.
[0044]
According to the configuration of the above-described embodiment, the dielectric layer 27 has at least one concave portion 27a for each discharge cell 35, and the film of the dielectric layer 27 is formed in a region where the bus electrodes 24b and 25b are present. When the thickness is increased, the capacitance in the region is reduced and the charge generated on the surface is suppressed, so that the discharge in the region is suppressed. Further, in a region where the thickness of the dielectric layer 27 is large, the discharge starting voltage increases, and therefore, the discharge in that portion is suppressed. That is, as shown in FIG. 3, according to the configuration of the above-described embodiment, the discharge A is formed intensively on the bottom surface of the concave portion 27a which is a region where the dielectric layer 27 has a small thickness. . On the other hand, in the structure without the concave portion 27a as shown in FIG. 4, since the thickness of the dielectric layer 27 is constant, the capacitance is constant on the surface of the dielectric layer 27, and the discharge B Since the light spreads to the vicinity of the electrodes 24b and 25b and the emitted light causes the phosphor layer in the portion shielded by the bus electrodes 24b and 25b to emit light, the efficiency is reduced.
[0045]
In addition, when the discharge spreads to the vicinity of the partition 32, the electron temperature is lowered by the partition 32, which may lower the efficiency. Further, when the discharge is performed in the vicinity of the partition 32, the partition 32 is negatively charged. Positive ions may be attracted, etched by ion bombardment, and the etched partition walls 32 may accumulate on the phosphor layers 33R, 33G, and 33B, causing a problem that the characteristics may be deteriorated. In the above-described configuration, by forming the concave portion 27 a inside the partition 32, it is possible to suppress the discharge from spreading to the vicinity of the partition 32.
[0046]
The shape of the concave portion 27a may be a shape such as a cylinder, a cone, a triangular prism, or a triangular pyramid other than the shape described above, and is not limited to the shape in the above embodiment.
[0047]
Here, in the above-described configuration, the firing of the dielectric material when forming the dielectric layer 27 is performed at a temperature lower than the softening point temperature.
[0048]
That is, in order to increase the efficiency of the PDP, the dielectric layer 27 used for the front panel 21 is required to take out the light emitted from the phosphor layers 33R, 33G, and 33B without blocking. The transmittance of the body layer 27 is required to be high. Therefore, conventionally, the firing temperature of the dielectric layer 27 is set to a temperature several tens of degrees higher than the softening point of the dielectric layer 27 with the main purpose of maintaining the transmittance as high as possible by promoting the sintering of the dielectric material. Was often set to For example, for a dielectric material having a softening point of 580 ° C., the firing temperature is set to 590 ° C., whereby the transmittance including the substrate 23 is set to about 70%. However, the present inventor examined the relationship between various firing temperatures and the transmittance at that time for this dielectric material. As a result, the firing temperature was set to ± 30 ° C. with respect to the softening point temperature (the softening point temperature was When the temperature is 580 ° C. and 550 ° C. to 610 ° C.), it is confirmed that the sintering is insufficient on the low temperature side and bubbles grow on the high temperature side, but the transmittance is reduced by about 1 to 5%. are doing. Further, when firing is performed at a temperature lower than the softening point temperature by 50 ° C. or more (530 ° C. when the softening point temperature is 580 ° C.), the dielectric material hardly softens, and therefore sintering is not accelerated. It has been confirmed that the transmittance also decreases to less than 50%.
[0049]
Therefore, based on the above results, in the present invention, while aiming not to greatly reduce the transmittance, the shape change such as sharpness of the end of the concave portion 27a due to softening and solidification when firing the dielectric material. It is also intended to suppress the occurrence of, and for that purpose, the temperature is lower than the softening point temperature, the lower limit is about 50 ° C. as described above, and the baking is preferably performed at about 30 ° C. in consideration of the influence of process variations. is there.
[0050]
According to the firing of the dielectric material as described above, since the dielectric material is softened and does not melt, the shape change such as the shrinkage at the time of solidification and the rise of the end of the concave portion 27a may occur. As a result, the concave portion 27a can be formed on the surface of the dielectric layer 27 with high accuracy.
[0051]
It should be noted that the firing at the softening point temperature or lower as described above causes a slight decrease in the transmittance of the dielectric layer 27. However, in the above-described configuration, the concave portion 27a is formed on the surface of the dielectric layer 27. Is formed, and the discharge is restricted in the concave portion 27a. Therefore, the portion that substantially contributes to the transmission of the emitted light generated by the discharge is the concave portion 27a in which the thickness of the dielectric layer 27 is small, Therefore, even if the transmittance of the dielectric layer 27 is slightly reduced, the thickness of the dielectric layer 27 is reduced in the concave portion 27a, thereby affecting the amount of emitted light transmitted through the dielectric layer 27. It will be suppressed.
[0052]
In addition, the dielectric material becomes the dielectric layer 27 which is a glass sintered body by firing, and the glass powder to be contained is, for example, ZnO-B ₂ O ₃ -SiO ₂ System mixture, PbO-B ₂ O ₃ -SiO ₂ System mixture, PbO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ System mixture, PbO-ZnO-B ₂ O ₃ -SiO ₂ System mixture, Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ System mixtures and the like.
[0053]
Next, FIGS. 5 to 8 show an example of a plasma display panel according to another embodiment of the present invention. The same elements as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.
[0054]
The difference from the configuration shown in FIGS. 1 to 3 is that the dielectric layer 27 has a multilayer structure, and at least the uppermost dielectric layer of each of the layers constituting the dielectric layer 27 has a softening point temperature of the dielectric material. It is formed by firing at a lower temperature.
[0055]
FIGS. 5 to 8 show an example of a multilayer structure in which the dielectric layer 27 has a two-layer structure, that is, a lower dielectric layer 27 b formed on the front substrate 23 so as to cover the display electrode 26, FIG. 3 is an enlarged view of a discharge cell portion in a case where the discharge cell portion is formed of an upper dielectric layer 27c formed on the discharge space side so as to cover the discharge space, and at least the uppermost layer of each of the layers 27b and 27c forming the dielectric layer 27 is shown. The upper dielectric layer 27c is formed by firing a dielectric material at a temperature lower than its softening point.
[0056]
According to the configuration of the above-described embodiment, the uppermost dielectric layer 27c is baked at a temperature lower than the softening point temperature of the dielectric material for forming itself. Similar to the configuration shown in FIG. 3, the problem that a shape change such as a sharp end of the concave portion 27a occurs is suppressed.
[0057]
Here, assuming that each layer constituting the dielectric layer 27 is formed by firing a dielectric material at a temperature lower than the softening point temperature of the dielectric layer below the layer, for example, FIGS. In the case of the configuration shown in FIG. 2, after the lower dielectric layer 27b is formed, a dielectric material for forming the upper dielectric layer 27c is applied, dried, and fired. Is suppressed from being re-softened, so that a more stable concave portion 27a can be formed.
[0058]
Here, the softening point temperature is adjusted by adjusting the composition ratio of PbO contained in the dielectric material or SiO 2. ₂ Can be carried out by changing the composition ratio. In general, when the composition ratio of PbO is increased, the softening point decreases, ₂ When the composition ratio of is decreased, the softening point similarly decreases. For example, as a glass powder having a softening point of around 600 ° C., 45 wt% to 65 wt% of lead oxide (PbO) and boron oxide (B ₂ O ₃ ) 10% to 30% by weight of silicon oxide (SiO ₂ 10% -30% by weight, calcium oxide (CaO) 1% -10% by weight as an additive, aluminum oxide (Al ₂ O ₃ ) A composition having a composition of 0% to 3% by weight can be mentioned. On the other hand, to increase the softening point by 30 ° C. can be realized by increasing the percentage by weight of PbO by 5% to 10%.
[0059]
The concave portion 27a on the surface of the dielectric layer 27 may be formed, for example, by forming the upper dielectric layer 27c by half etching using a photolithographic method, as shown in FIG. For example, a configuration as shown in FIG. 8 formed by hollowing out each time and forming the bottom surface of the concave portion 27a to be the surface of the lower dielectric layer 27b. The structure shown in FIG. 8 is, for example, a photosensitive dielectric material formed by first forming a lower dielectric layer 27b and then adding a photosensitive material to a dielectric material for forming an upper dielectric layer 27c. The material is applied on the lower dielectric layer 27b, exposed and developed so as to form a hole, and then baked, so that a hole is formed in the upper dielectric layer 27c. Thus, a configuration having the concave portion 27a as the dielectric layer 27 is obtained. Further, the configuration of the concave portion 27a by such a forming method is preferable because the accuracy in the depth direction of the concave portion 27a is improved.
[0060]
In the configuration described above, the protective layer 28 is formed on the surface of the dielectric layer 27 including the concave portion 27a.
[0061]
Further, in the configuration described above, the filler can be contained in the dielectric layer 27, whereby the shape can be further maintained, and the swelling can be suppressed. Here, examples of the filler component include titanium oxide, alumina, calcium carbonate, quartz glass, magnesium hydroxide, barium sulfate, and calcium sulfate.
[0062]
In order to form on the front plate, it is necessary to maintain transparency even if a filler is added, and more preferably, a material having a refractive index close to that of the dielectric glass is preferable. For example, if the refractive index of the dielectric glass is around 1.7, it is preferable that the refractive index of the filler be 1-2. Further, it is more preferable to set 1.5 to 1.9. Here, alumina is 1.56, calcium carbonate is 1.53-1.61, quartz glass is 1.46, magnesium hydroxide is 1.54, barium sulfate is 1.65, and calcium sulfate is 1.57. It is a material having a preferable refractive index among the above-mentioned fillers. Conversely, titanium oxide has a refractive index of 2.76 and may lose transparency.
[0063]
【The invention's effect】
As described above, according to the plasma display panel of the present invention, it is possible to accurately form a three-dimensional structure such as a concave portion on the surface of a dielectric layer, suppress interference between discharge cells, and achieve high efficiency. A plasma display panel can be realized.
[Brief description of the drawings]
FIG. 1 is a sectional perspective view showing a schematic configuration of a plasma display panel according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a schematic configuration of a discharge cell unit in the plasma display panel according to one embodiment of the present invention.
FIG. 3 is a sectional view showing a schematic configuration of a discharge cell unit in the plasma display panel according to one embodiment of the present invention;
FIG. 4 is a cross-sectional view showing a schematic configuration of a discharge cell unit in a conventional plasma display panel.
FIG. 5 is a sectional perspective view showing a schematic configuration of a plasma display panel according to another embodiment of the present invention.
FIG. 6 is a perspective view showing a schematic configuration of a discharge cell unit in a plasma display panel according to another embodiment of the present invention.
FIG. 7 is a sectional view showing a schematic configuration of a discharge cell unit in a plasma display panel according to another embodiment of the present invention.
FIG. 8 is a sectional view showing a schematic configuration of a discharge cell unit in a plasma display panel according to another embodiment of the present invention.
FIG. 9 is a sectional perspective view showing a schematic configuration of a conventional plasma display panel.
FIG. 10 is a sectional view showing a schematic configuration of a discharge cell unit in a conventional plasma display panel.
[Explanation of symbols]
21 Front panel
22 Rear panel
23 (front side) board
24 scanning electrodes
25 Sustain electrode
26 Display electrode
27 Dielectric layer
27a recess
29 (back side) substrate
30 address electrode
32 partition
33 phosphor layer
34 Discharge space
35 Discharge cell

Claims (8)

A pair of front and rear substrates arranged opposite to each other so as to form a discharge space partitioned by partitions between the substrates, and arranged on the front substrate so that discharge cells are formed between the partitions. A plurality of display electrodes formed on the front side substrate so as to cover the display electrodes, a dielectric layer having at least one concave portion for each discharge cell on the surface on the discharge space side, and between the display electrodes A phosphor layer that emits light by the discharge of the plasma display panel, wherein the dielectric layer is formed by firing a dielectric material at a temperature lower than its softening point. The dielectric layer having the concave portion has a multilayer structure, and at least the uppermost dielectric layer of each layer constituting the dielectric layer is formed by firing a dielectric material at a temperature lower than its softening point temperature. The plasma display panel according to claim 1, wherein 3. The plasma display panel according to claim 2, wherein each of the layers constituting the dielectric layer is formed by firing a dielectric material at a temperature lower than the softening point of the dielectric layer below the layer. 3. The plasma display panel according to claim 2, wherein the concave portion is formed by cutting out an upper dielectric layer so that a bottom surface of the concave portion is a surface of the lower dielectric layer. The plasma display panel according to any one of claims 1 to 3, wherein the lower limit of the temperature lower than the softening point temperature is a temperature lower by 50 ° C than the softening point temperature. The plasma display panel according to any one of claims 1 to 4, wherein the dielectric layer includes a filler. The plasma display panel according to claim 6, wherein the filler has a refractive index of 1 to 2. The dielectric _{layer, ZnO-B 2 O 3 -SiO} 2 based _{mixtures, PbO-B 2 O 3 -SiO} 2 based _{mixtures, PbO-B 2 O 3 -SiO} 2 -Al 2 O 3 based mixtures, PbO _{-ZnO-B 2} O 3 -SiO ₂ based _mixture, characterized by being formed by a dielectric material containing glass powder selected from among _{Bi 2 O 3 -B 2 O 3} -SiO 2 based mixtures The plasma display panel according to any one of claims 1 to 4, and 6.

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