JP3861696B2 - Sheet-like dielectric material and method for manufacturing plasma display panel using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet-like dielectric material and a method for manufacturing a plasma display panel using the same.
[0002]
[Prior art]
In recent years, expectations for large screens and wall-mounted televisions as interactive information terminals have increased. There are many display devices for this purpose, such as liquid crystal display panels, field emission displays, electroluminescence displays, etc., some of which are commercially available and some are under development. Among these display devices, the plasma display panel (hereinafter referred to as PDP) is a self-luminous type capable of displaying beautiful images and is easy to enlarge. For this reason, a display using PDP has excellent visibility. It is attracting attention as a thin display device, and high definition and large screen are being promoted.
[0003]
This PDP is broadly divided into AC type and DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type. From the viewpoint of high definition, large screen, and ease of manufacturing. At present, AC type and surface discharge type PDPs are becoming mainstream.
[0004]
FIG. 3 shows an example of the panel structure of the PDP. As shown in FIG. 3, the PDP is composed of a front panel 1 and a back panel 2.
[0005]
The front panel 1 is formed by arranging a plurality of stripe-shaped display electrodes 4 on a transparent front substrate 3 such as a glass substrate made of sodium borosilicate glass by a float method, and the display electrodes 4 A dielectric layer 5 is formed so as to cover the group, and a protective film 6 made of MgO is formed on the dielectric layer 5. The display electrode 4 is composed of a transparent electrode 4a and a bus electrode 4b made of Cr / Cu / Cr or Ag electrically connected to the transparent electrode 4a. Although not shown, a plurality of black stripes as light shielding films are formed between the display electrodes 4 in parallel with the display electrodes 4.
[0006]
Further, the rear panel 2 forms address electrodes 8 made of Cr / Cu / Cr, Ag, or the like in a direction orthogonal to the display electrodes 4 on a rear substrate 7 disposed opposite to the front substrate 3. In addition, a dielectric layer 9 is formed so as to cover the address electrodes 8, and a plurality of stripe-shaped partition walls 10 are formed in parallel with the address electrodes 8 on the dielectric layer 9 between the address electrodes 8. The phosphor layer 11 is formed on the side surfaces between 10 and the surface of the dielectric layer 9. For color display, the phosphor layer 11 is usually arranged in order of three colors of red, green and blue.
[0007]
The front panel 1 and the rear panel 2 are arranged so that the substrates 3 and 7 are opposed to each other with a minute discharge space so that the display electrodes 4 and the address electrodes 8 are orthogonal to each other, and the periphery is a sealing member. And a discharge gas obtained by mixing neon and xenon in the discharge space is sealed at a pressure of about 66500 Pa (500 Torr) to form a panel.
[0008]
The discharge space of the panel is divided into a plurality of sections by the barrier ribs 10, and a display electrode 4 is provided between the barrier ribs 10 so that a plurality of discharge cells serving as light emitting pixel regions are formed. 4 and the address electrode 8 are arranged orthogonally. In this PDP, a discharge is generated by a periodic voltage applied to the display electrode 4 and the address electrode 8, and the phosphor layer is irradiated with ultraviolet rays by the discharge to convert it into visible light, thereby displaying an image. Done.
[0009]
In such a PDP, Ag, Cr—Cu—Cr, or the like is used for the address electrode 8 and the bus electrode 4 b of the display electrode 4. Of these, a method for producing an electrode using Ag is a screen printing method. In addition, there are a method using an Ag paste containing Ag, a resin, a solvent, and the like, and a method using a film containing Ag, a resin, etc., as in a laminating method. In any case, it is necessary to perform heating and baking at 500 ° C. or higher for the purpose of removing the resin or for fusing Ag together to increase the conductivity.
[0010]
Furthermore, the dielectric layer covering these electrodes is an indispensable material for generating plasma, and has a function of higher discharge efficiency and allowing light emitted from the phosphor on the back plate to pass well. It is an important component.
[0011]
In addition, the dielectric layer has been conventionally applied by a method such as screen printing or die coating, which includes a glass paste composition containing a powder such as low melting point lead glass and a binder resin (an organic substance constituting the film forming material layer). It was formed by heating and baking at 500 ° C. or higher.
[0012]
The thickness of the film-forming material layer formed on the glass substrate is 1.3 to 2 times the film thickness of the dielectric layer to be formed in consideration of the reduction in film thickness associated with the removal of the organic substance in the baking process. For example, in order to set the thickness of the dielectric layer to 5 to 40 μm, it is necessary to form a film forming material layer having a thickness of about 7 to 80 μm.
[0013]
However, when the glass paste composition is applied by a screen printing method, the thickness of the coating film formed by one application process is about 5 to 25 μm. In the case of forming by screen printing, multiple printing is required multiple times, and there is a decrease in work efficiency due to complicated processes, a decrease in film thickness distribution, a decrease in smoothness, an increase in the probability of occurrence of defects, etc. I can't avoid it. Also in the case of the die coating method, the film thickness distribution at the start and end of the coating is poor, which causes variations in dielectric characteristics and causes a decrease in drive voltage margin.
[0014]
In response to these problems, for example, as disclosed in JP-A-10-291834, a sheet-like dielectric material in which a glass paste composition is formed on a support film is used and bonded by a method such as a laminating method. There has been proposed a method of forming a dielectric layer by heating and baking at 500 ° C. or higher after being applied.
[0015]
The sheet-shaped dielectric material will be described with reference to FIG. 4. FIG. 4 (a) is a schematic configuration diagram showing the sheet-shaped dielectric material 12 wound in a roll shape, and FIG. It is sectional drawing which shows the layer structure of the sheet-like dielectric material 12 of X part of 4 (a). The sheet-like dielectric material 12 shown in FIG. 4 includes a support film 13, a film forming material layer 14 formed on the surface of the support film 13 so as to be peelable, and can be easily peeled off on the surface of the film forming material layer 14. The cover film 15 is formed.
[0016]
By using the sheet-like dielectric material 12 on which the film forming material has been prepared in advance, even a dielectric layer having a large film thickness, for example, a dielectric layer having a thickness of 5 to 40 μm, can be efficiently formed. It is possible to improve the process in the body layer forming process and improve the manufacturing efficiency of the PDP. In addition, it is possible to form a dielectric layer that is excellent in film thickness uniformity and surface smoothness and has no defects such as pinholes and cracks.
[0017]
On the other hand, with the demand for higher definition and higher brightness of the PDP, for example, as disclosed in JP-A-8-250029, to control the discharge and suppress the discharge at the shielded portion as much as possible. A dielectric layer having a new structure in which the dielectric layer is three-dimensionally configured has been proposed.
[0018]
In order to fabricate a dielectric layer having a three-dimensional structure, it is necessary to pattern a sheet-like dielectric material. This technique is disclosed, for example, in JP-A-11-231525. The contents are shown in FIGS.
[0019]
As shown in FIGS. 5A to 5C, a sheet-like dielectric material 12 in which a film-forming material layer 14 made of an inorganic powder-dispersed paste is formed on a support film 13 is transferred onto a glass substrate 16, A resist layer 17 is formed thereon as shown in FIG. 5 (d), and then, as shown in FIGS. 5 (e) and (f), the resist layer 17 is exposed to a predetermined pattern by aligning an exposure mask 18. Development is performed to form a resist layer 17 having a predetermined pattern, and the resist layer 17 having the predetermined pattern is used as a mask to form a film forming material layer of an inorganic powder-dispersed paste as shown in FIGS. In this method, after etching 14 into a predetermined pattern shape, the resist layer 17 is removed, and then baking is performed at a predetermined temperature as shown in FIG. 5 (i).
[0020]
[Problems to be solved by the invention]
However, the conventional method for producing a three-dimensional structure of a PDP dielectric layer using a sheet-like dielectric material and a patterning process has the following problems.
[0021]
That is, in the three-dimensional structure of the dielectric layer of the PDP, for example, as shown in FIGS. 6A and 6B, when the concave portion 20 is provided in the dielectric layer 5 of the front panel 1 for each light emitting pixel region, the dielectric layer 5 is required to produce a thick portion 5a and a thin portion 5b with a predetermined pattern without variation. In addition, FIG.6 (b) is a figure which shows the cross section at the time of cut | disconnecting by the AA line of Fig.6 (a).
[0022]
In the above conventional patterning method, for example, it is necessary to stop the etching in the middle of FIG. 5G and leave the thin portion 5b in the dielectric layer 5. However, if the etching is stopped in the middle in this way, it is as large as PDP. In the case of a panel having an area, the variation in etching of the entire panel becomes the variation in shape and depth as it is, and the three-dimensional structure of the dielectric layer cannot be obtained with high accuracy throughout.
[0023]
Therefore, after the first dielectric layer is first baked and formed with the sheet-like dielectric material corresponding to the thickness of the thin portion, the above-described conventional dielectric sheet material is used to match the thickness of the thick portion. It is conceivable to obtain a three-dimensional structure by forming the second dielectric layer by the patterning method, but in this case, it is necessary to transfer the sheet-like dielectric material to the substrate twice with high accuracy, and the process is complicated. Become. Further, from the viewpoint of the discharge starting voltage in the PDP, if the first dielectric layer as a lower layer has a distribution in the film thickness and the portion where the film thickness is reduced is used as the seed discharge, the discharge voltage can be further increased. However, in the method of forming a lower layer as described above by firing and then applying a dielectric on the upper portion and patterning it, the shape of the lower layer could not be changed.
[0024]
The present invention has been made in view of such problems, and an object of the present invention is to be able to stably and accurately form a dielectric layer having a three-dimensional structure with high work efficiency.
[0025]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides a photosensitive dielectric forming material layer containing glass powder, a binder resin and a photosensitive resin, and the glass powder and the binder formed on the photosensitive dielectric forming material layer. A sheet-shaped dielectric material provided with a dielectric-forming material layer containing a resin is used, and the dielectric-forming material layer and the photosensitive dielectric are formed on the substrate so that the dielectric-forming material layer is on the substrate side. After the material layer is transferred to the substrate, the photosensitive dielectric forming material layer is exposed and developed using a mask having a predetermined pattern, thereby forming a dielectric layer having a predetermined pattern shape.
[0026]
With such a configuration, when a three-dimensional structure of a dielectric layer is produced, a dielectric layer having a thick part and a thin part is produced with uniform work efficiency by using one type of sheet-like dielectric material. It is possible to suppress variation in shape and depth within a large-area panel.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
  That is, the invention according to claim 1 of the present invention comprises a photosensitive dielectric forming material layer formed on a support film and containing glass powder, a binder resin and a photosensitive resin, and the photosensitive dielectric forming material. A dielectric-forming material layer formed on the layer and containing glass powder and a binder resin;And the decomposition temperature or combustion temperature or volatilization temperature of the binder resin contained in the photosensitive dielectric forming material layer is equal to or lower than the decomposition temperature or combustion temperature or volatilization temperature of the binder resin of the dielectric forming material layer. is thereThis is a sheet-like dielectric material.
[0028]
  The invention according to claim 2 is characterized in that the photosensitive dielectric forming material layer and the dielectric forming material layer contain a solvent. Also,In the invention according to claim 3, the decomposition temperature or combustion temperature or volatilization temperature of the solvent contained in the photosensitive dielectric forming material layer is not more than the decomposition temperature, combustion temperature or volatilization temperature of the solvent of the dielectric forming material layer. It is characterized by being.
[0029]
  Furthermore, the present inventionClaim 4In the invention described in, a photosensitive dielectric forming material layer containing glass powder, a binder resin and a photosensitive resin, and a dielectric formed on the photosensitive dielectric forming material layer and containing glass powder and a binder resin. A sheet-like dielectric material having a body-forming material layer is superimposed on the substrate so that the dielectric-forming material layer is on the substrate side, and the dielectric-forming material layer and the photosensitive dielectric-forming material layer are transferred to the substrate. A transfer step, a pattern formation step in which the transferred photosensitive dielectric forming material layer is exposed and developed using a mask having a predetermined pattern, and then the photosensitive dielectric forming material layer and the dielectric forming material layer are baked. Firing process for forming the dielectric layerAnd the decomposition temperature or combustion temperature or volatilization temperature of the binder resin contained in the photosensitive dielectric forming material layer of the sheet-like dielectric material is the decomposition temperature of the binder resin of the dielectric forming material layer or Below combustion temperature or volatilization temperatureThis is a method for manufacturing a plasma display panel.
[0030]
  AndClaim 5In the invention described in, at least one recess is formed in the dielectric layer for each light emitting pixel region of the plasma display panel by exposing and developing the photosensitive dielectric forming material layer in the pattern forming process, and the bottom surface of the recess The thickness of the dielectric layer is reduced.
[0031]
  Also,Claim 6According to the invention described in the item 1, in the method for manufacturing a plasma display panel, the photosensitive dielectric forming material layer and the dielectric forming material layer contain a solvent, andClaim 7In the invention described in the above, the decomposition temperature or combustion temperature or volatilization temperature of the solvent contained in the photosensitive dielectric forming material layer is lower than the decomposition temperature, combustion temperature or volatilization temperature of the solvent of the dielectric forming material layer. It is a feature.
[0032]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings of FIGS.
[0033]
First, a sheet-shaped dielectric material according to an embodiment of the present invention will be described with reference to FIG. 1. FIG. 1A is a schematic configuration diagram showing a sheet-shaped dielectric material 21 wound in a roll shape. FIG. 1B is a cross-sectional view showing the layer structure of the sheet-like dielectric material 21 in the X part of FIG. As shown in FIG. 1, the sheet-like dielectric material 21 is formed on a support film 22, a photosensitive dielectric forming material layer 23 formed on the support film 22, and the photosensitive dielectric forming material layer 23. The dielectric forming material layer 24 and the cover film 25 disposed on the dielectric forming material layer 24 are laminated.
[0034]
Here, the dielectric forming material layer 24 and the photosensitive dielectric forming material layer 23 contain glass powder and a binder resin as essential components, and the photosensitive dielectric forming material layer 23 contains a photosensitive resin. Yes.
[0035]
The support film 22 constituting the sheet-like dielectric material is preferably a resin film having heat resistance and solvent resistance and flexibility. Since the support film 22 has flexibility, a film forming material layer having a uniform film thickness can be formed by a roll coater or the like, and the film forming material layer is stored in a roll shape. Can do. Examples of the resin that forms the support film 22 include polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, polyfluoroethylene, and other fluorine-containing resins, nylon, and cellulose.
[0036]
The photosensitive dielectric forming material layer 23 and the dielectric forming material layer 24 constituting the sheet-like dielectric material are fired to become a glass sintered body (dielectric layer), and the dielectric forming material layer As a glass powder contained in 24, for example, ZnO-B₂O_Three-SiO₂System mixture, PbO-B₂O_Three-SiO₂System mixture, PbO-B₂O_Three-SiO₂-Al₂O_ThreeSystem mixture, PbO-ZnO-B₂O_Three-SiO₂Mention may be made of mixtures of systems.
[0037]
The photosensitive resin contained in the photosensitive dielectric forming material layer 23 includes at least an alkali developing binder resin, a reactive monomer, and a photopolymerization initiator, and as additives, a sensitizer and a polymerization terminator. , A chain transfer agent, a leveling agent, a dispersant, a plasticizer, a stabilizer, an antifoaming agent and the like can be contained as necessary.
[0038]
Representative examples of the binder resin of the present invention include acrylic and cellulose. In this case, examples of the resin used for the photosensitive dielectric forming material layer and the dielectric forming material layer include butyl (meth) acrylate, ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, and 2-ethoxy. Although ethyl (meth) acrylate can be mentioned, it is not restricted to this.
[0039]
In addition, as the binder resin contained in the dielectric forming material layer 24, the binder resin of the photosensitive dielectric forming material layer 23 is decomposed or burned or volatilized by the binder resin of the dielectric forming material layer 24. Is also low. Most preferably, an acrylic resin is used for the photosensitive dielectric forming material, and a cellulose resin is used for the dielectric forming material layer.
[0040]
Thereby, two layers having different functions can be formed at the same time, and the number of steps can be greatly reduced. In addition, when two layers are produced using two different sheets, two support films are required for each. However, according to the present invention, the support film that becomes extremely large as waste is halved. Can reduce the load on the environment.
[0041]
Further, in manufacturing a PDP, the sheet-like dielectric material is transferred onto a glass substrate, and is bonded stepwise from a layer formed on the glass substrate when the dielectric forming material layer 24 is dried or baked. The adhesive resin can be volatilized, burned or decomposed, and the lower binder resin is gasified after all the upper binder resin is removed, so that it can easily pass through the upper layer. For this reason, two layers can be fired simultaneously, and the number of steps can be reduced. Moreover, energy consumption can be reduced by reducing the number of firings, and the burden on the environment can be reduced. These will be described in detail in the PDP manufacturing method described later.
[0042]
Furthermore, the dielectric forming material layer 24 and the photosensitive dielectric forming material layer 23 contain glass powder and a binder resin as essential components, and the photosensitive dielectric forming material layer 23 contains a photosensitive resin, and A solvent may be contained in both the two layers.
[0043]
In this case, as a solvent used for the photosensitive dielectric forming material layer 23 and the dielectric forming material layer 24, an appropriate viscosity (for example, 500 to 10) is applied to the dielectric forming material layer 24 and the photosensitive dielectric forming material layer 23. 000 cp), and is preferably one that can be easily removed by evaporation, for example, methyl isobutyl ketone, propylene glycol monomethyl ether, turpentine oil, ethyl cellosolve, methyl cellosolve, terpineol, butyl carbitol acetate. Butyl carbitol, benzyl alcohol, methyl lactate, ethyl lactate, butyl cellosolve acetate, ethyl-3-ethoxypropionate, butyl cellosolve and the like.
[0044]
The solvent is characterized in that the dielectric forming material layer 24 and the photosensitive dielectric forming material layer 23 have different decomposition, combustion or volatilization temperatures. Preferably, the solvent of the photosensitive dielectric forming material layer 23 formed on the support film 22 has a lower decomposition or combustion or volatilization temperature than the solvent of the dielectric forming material layer 24.
[0045]
Here, for example, as a combination of the above-mentioned solvents, a material having a decomposition or combustion or volatilization temperature lower than that of at least the dielectric forming material layer 24 is selected as the photosensitive dielectric forming material layer 23. Preferably, turpentine oil (boiling point 155 to 165 ° C.) is selected for the photosensitive dielectric forming material layer 23 and terpineol (boiling point about 180 ° C.) is selected for the dielectric forming material layer 24. Thereby, the effect similar to the effect described by the said binder resin can be expressed.
[0046]
As a manufacturing method of the sheet-like dielectric material 21 used here, the photosensitive dielectric forming material layer 23 is formed on the support film 22, and the dielectric forming material layer 24 is further formed thereon. It can manufacture by providing the cover film 25 by pressure bonding. The dielectric forming material layer 24 is formed by applying the dielectric forming material layer 24 made of a glass paste composition containing at least glass powder and a binder resin, preferably containing a solvent, and then applying the coating film. The method of drying and removing a part or all of the said solvent can be mentioned. Examples of a method for applying the dielectric forming material layer 24 made of the glass paste composition include a coating method using a roller coater, a coating method using a blade coater such as a doctor blade, and a coating method using a curtain coater.
[0047]
Next, in the method for manufacturing the PDP according to the present invention, the manufacturing process of the front panel will be described with reference to FIG.
[0048]
In the first step shown in FIG. 2A, ITO or SnO is formed on a glass substrate 31 as a front substrate of the front panel.₂This is a step of uniformly forming a transparent electrode material film 32 made of or the like by sputtering. At this time, the film thickness of the transparent electrode material film 32 is about 100 nm.
[0049]
The second step shown in FIG. 2B is a step of forming the transparent electrode 33 by patterning the transparent electrode material film 32 into a desired shape using a photolithography method. A positive resist mainly composed of a novolak resin is applied in a film thickness of 1.5 to 2 μm, and ultraviolet rays are exposed through an exposure dry plate having a desired pattern to cure the resist. The ultraviolet light source at this time is an ultra-high pressure mercury lamp, and the amount of light is 300 mJ / cm.²It is. 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, etching is performed, unnecessary portions are removed, and finally the resist is removed to form the transparent electrode 33.
[0050]
A third step shown in FIG. 2C is a step of applying the black electrode material film 34. The black electrode material film 34 is made of RuO.₂Black pigments, glass frit (PbO-B₂O_Three-SiO₂Series and Bi₂O_Three-B₂O_Three-SiO₂System), a polymerization initiator, a photocurable monomer, and an organic solvent as components, and a negative photosensitive paste is uniformly applied to the glass substrate 31 using a screen printing method. Thereafter, the solvent contained in the paste is removed from the coating film by a drying process at 90 ° C. for 10 minutes using an infrared drying oven.
[0051]
The fourth step shown in FIG. 2D is a step of forming the metal electrode material film 35 on the black electrode material film 34. In this process, the material used is a conductive material such as Ag, glass frit (PbO-B₂O_Three-SiO₂Series and Bi₂O_Three-B₂O_Three-SiO₂System, etc.), a polymerization initiator, a photocurable monomer, and a negative photosensitive paste containing an organic solvent as components.
[0052]
A fifth step shown in FIG. 2E is a step of forming the bus electrode 36. The exposed portion is cured by irradiating the electrode material film composed of the metal electrode material film 35 and the black electrode material film 34 with ultraviolet rays through an exposure dry plate having a desired pattern. The ultraviolet light source at this time is an ultra-high pressure mercury lamp, and the amount of light is 300 mJ / cm.²It is. Thereafter, development is performed using an alkaline developer (0.3 wt% sodium carbonate aqueous solution) to form a pattern, and then baking is performed in air at a temperature equal to or higher than the softening point of the glass material to fix the electrode to the substrate.
[0053]
Thus, by forming the bus electrode 36 on the transparent electrode 33, the display electrode of the front panel can be formed.
[0054]
In the sixth step shown in FIG. 2 (f), a dielectric material layer composed of two layers, a dielectric forming material layer 37 and a photosensitive dielectric forming material layer 38, is formed using the sheet-like dielectric material 21 described above. It is a process of forming. The dielectric material layer is peeled off from the cover film 25 of the sheet-like dielectric material 21, and then the sheet-like dielectric material 21 is overlapped so that the surface of the dielectric material layer is in contact with the glass substrate 31, and from the support film 22 side. The glass substrate 31 is fixed by pressure with a heating roller. Thereafter, the support film 22 is peeled off from the dielectric material layer fixed on the glass substrate 31. At this time, the means used for pressure bonding may be a simple roller that does not heat other than the heating roller.
[0055]
The seventh step shown in FIG. 2G is a step of exposing the photosensitive dielectric forming material layer 38. The exposed portion is cured by irradiating the photosensitive dielectric forming material layer 38 of the dielectric material layer with ultraviolet rays through an exposure mask 39 having openings of a desired pattern. The ultraviolet light source at this time is an ultra-high pressure mercury lamp, and the amount of light is 600 mJ / cm.²It is.
[0056]
The eighth step shown in FIG. 2H is a step of forming a three-dimensional dielectric layer having a thick portion and a thin portion by forming a recess in the light emitting pixel region. The photosensitive dielectric forming material layer 38 of the dielectric material layer is developed using an alkaline developer (0.3 wt% sodium carbonate aqueous solution), and the non-exposed portion of the photosensitive dielectric forming material layer 38 is removed.
[0057]
At this time, the binder resin constituting the dielectric forming material layer 37 is not removed because it is not soluble in the developer, or the etching rate is lower than the etching rate of the photosensitive dielectric forming material layer 38. Therefore, only a small region near the interface with the first dielectric forming material layer 37 is removed. Therefore, a dielectric material layer having a desired three-dimensional structure is formed. At this time, the film thicknesses of the dielectric material layers in the non-exposed part and the exposed part are desirably 30 μm and 20 μm, respectively.
[0058]
Thereafter, baking is performed in air at a temperature equal to or higher than the softening point of the glass material to fix the glass component, thereby forming a dielectric layer having a three-dimensional structure.
[0059]
Here, as described above, the present invention is characterized in that the solvent of the photosensitive dielectric material layer 38 has a lower decomposition, combustion or volatilization temperature than the solvent of the dielectric material layer 37. Therefore, at the time of firing, the solvent of the photosensitive dielectric forming material layer 38 on the upper layer side decomposes or burns or volatilizes first on the basis of the glass substrate 31, and then the solvent of the lower dielectric forming material layer 37 decomposes or delays later. Since it burns or volatilizes, it can easily pass through the upper layer, and two layers can be fired simultaneously.
[0060]
Similarly, the binder resin of the photosensitive dielectric forming material layer 38 is characterized by having a lower decomposition, combustion or volatilization temperature than the binder resin of the dielectric forming material layer 37. The binder resin of the conductive dielectric forming material layer 38 decomposes or burns or volatilizes first, and then the binder resin of the lower dielectric forming material layer 37 decomposes or burns or volatilizes later so that it easily slips through the upper layer. The two layers can be fired simultaneously. Therefore, in the past, two layers were fired separately, but the two layers can be fired at the same time, and the cost can be reduced by reducing the number of steps. In addition, since the power consumption can be reduced by reducing the number of firings, the process is friendly to the environment.
[0061]
Further, as an important function of the present invention, by firing the two layers simultaneously, the lower layer that becomes the bottom surface of the concave portion spontaneously removed by patterning is drawn by the stress at the time of contraction of the upper dielectric layer, The thickness of the bottom surface can be changed gently, the dielectric film thickness can be curved to be small, and the lower layer can be processed effectively.
[0062]
A ninth step shown in FIG. 2I is a step of forming the protective film 40. The protective film 40 is made of MgO and is uniformly formed on the dielectric layer by electron beam evaporation. At this time, the thickness of the protective film 40 is about 600 nm.
[0063]
Through the above steps, a PDP front panel having a desired three-dimensional dielectric is obtained.
[0064]
Next, in the manufacturing method of the PDP according to the present invention, the manufacturing method of the back panel will be described. First, the address electrodes are applied to the glass substrate as the back side substrate of the back panel manufactured by the float method in the same manner as the front panel. Form. A dielectric layer is formed thereon in the same manner as the front panel, and a partition is formed thereon.
[0065]
As a material to be used for forming the dielectric layer and the partition, a paste-like glass powder-containing composition (glass paste composition) containing glass powder, a binder resin and a solvent is prepared. After coating on the support film, the coating film is dried to form a film-forming material layer. The film-forming material layer formed on the support film is placed on the front surface of the glass substrate on which the address electrodes are formed. A dielectric layer can be formed on the surface of the glass substrate by fixing by transfer in the same manner as the panel and firing the film forming material layer fixed by this transfer.
[0066]
Thereafter, as a method for forming the partition wall, a photolithography method or a sandblast method can be used.
[0067]
Next, the rear panel can be obtained by applying phosphors corresponding to R, G, and B and firing to form a phosphor layer between the barrier ribs.
[0068]
Then, the front panel and the back panel manufactured in this way are positioned to face each other so that the display electrodes and the address electrodes intersect at a substantially right angle, and the periphery is sealed with a sealing material. After that, the gas in the space partitioned by the partition walls is exhausted, and then a discharge gas such as Ne and Xe is sealed to seal the gas space, so that the PDP having the configuration shown in FIG. Can be completed.
[0069]
By the way, in the PDP according to the present invention manufactured as described above, the dielectric layer has a lower layer dielectric formed on a front substrate such as a glass substrate, and at least one recess for each light emitting pixel region. A two-layer structure comprising an upper dielectric layer patterned into a predetermined shape so as to be formed. That is, the display electrodes in each row formed on the front substrate are arranged so as to be adjacent to each other with a discharge gap in each line of the matrix display, and a region surrounded by the partition walls and the pair of display electrodes is a light emitting pixel. A region is formed, and at least one recess is formed in the dielectric layer of each light emitting pixel region.
[0070]
In order to achieve high efficiency of the PDP, it is essential to control the discharge in each light emitting pixel region. In particular, in FIG. 3, in the spread of the discharge perpendicular to the display electrode 4, the bus electrode 4 b blocks the light emitted from the phosphor, so that it is necessary to suppress the discharge from spreading to the shielded portion. In addition, since there are no barrier ribs 10 in this direction, all the light emitted from the ultraviolet rays and phosphors leaking from the barrier ribs 10 is shielded by the black stripes. Furthermore, the spread of the discharge in the direction parallel to the display electrode 4 causes a decrease in efficiency due to a decrease in the electron temperature in the vicinity of the barrier rib 10.
[0071]
According to the manufacturing method of the present invention, as shown in FIG. 6A, the recess 20 having a depth of, for example, 20 μm is formed on the dielectric layer 5 of the front substrate 3 so as to be inside the bus electrode 4b and the partition 10. Since the capacitance of the bottom surface of the recessed portion 20 having a reduced film thickness increases due to the decrease in the dielectric film thickness, the wall charges formed in that portion are larger than those in other portions, and the film thickness is further increased. Since the discharge start voltage decreases due to the decrease, the discharge mainly occurs at the bottom surface of the recess 20.
[0072]
With such a configuration, discharge spreading horizontally and vertically on the display electrode 4 can be suppressed, and efficiency can be improved. In addition, although the shape of the recessed part 20 can consider a polygon, a cylinder, a cone, a rectangular parallelepiped, a trapezoid, etc., it is not restricted to this.
[0073]
Further, as shown in FIG. 6B, the film thickness of the side surface of the recess 20 may be gently changed. In this case, the spread of VUV generated by the discharge of the bottom surface can be used effectively. Further, by curving the bottom surface of the recess 20 so that the dielectric film thickness is small, the discharge voltage at the part where the film thickness is most reduced is lowered, so that an effect as a seed fire can be obtained.
[0074]
As another improvement in efficiency, there is a method of increasing the extraction efficiency of light emitted from the phosphor, that is, increasing the aperture ratio. In this case, the bus electrode 4b needs to be separated from the light emitting pixel region as much as possible. However, since the distance from the display electrode 4 of the adjacent cell running in parallel is narrowed, the movement of charges is facilitated and light emission is not desired. There is a problem that the cell emits light, so-called crosstalk, and display quality is remarkably deteriorated.
[0075]
In the manufacturing method of the present invention, the position where the wall charges are generated can be controlled by adjusting the shape of the recess 20, and the occurrence of crosstalk can also be prevented.
[0076]
Furthermore, as another method for improving the efficiency of PDP, many reports have been made to increase the Xe partial pressure, but in this case, the discharge start voltage also increases as the Xe partial pressure increases, and thus there is a trade-off relationship. . Therefore, it is necessary to reduce the discharge start voltage that increases with the Xe partial pressure by other methods. One possible method is to reduce the thickness of the dielectric layer. However, if the dielectric layer is made thinner, the probability of dielectric breakdown due to defects in the dielectric layer due to foreign matter or the like increases and the yield decreases. . In particular, since the bus electrode formed for the purpose of reducing the resistance is as thick as 4 to 7 μm, if the dielectric layer is made thin, the effective film thickness on the bus electrode is reduced, and the dielectric breakdown is concentrated near the bus electrode. There is.
[0077]
According to the manufacturing method of the present invention, it is possible to easily increase the thickness of the dielectric layer on the bus electrode where breakdown is most likely to occur. Since the thin part of the body layer has only a transparent electrode with a thickness of about 0.1 μm, the effective film thickness hardly changes, thereby combining the structure in which the concave part of the dielectric layer is formed and the increase in Xe partial pressure. By using these, it is possible to achieve both high yield and high efficiency of the PDP.
[0078]
In addition, from the viewpoint of improving the transmittance of the dielectric layer and limiting the discharge current, the bottom surface of the recess formed in the dielectric layer is preferably shaped so that the film thickness changes gently. When a two-layer sheet-like dielectric material is used by the method, the film thickness of the bottom surface of the lower layer can be gently changed by the lower layer being pulled by the upper layer due to the stress at the time of contraction of the upper dielectric layer. A dielectric layer having a recess having a shape in which the thickness of the bottom surface changes gently can be easily produced.
[0079]
【The invention's effect】
As described above, according to the present invention, in a PDP, it is possible to easily form a dielectric layer having a three-dimensional structure that is effective in reducing the discharge start voltage with high accuracy and stability. An effect is obtained.
[Brief description of the drawings]
FIGS. 1A and 1B are a schematic configuration diagram and a cross-sectional view showing a sheet-like dielectric material according to an embodiment of the present invention.
2A to 2I are process cross-sectional views illustrating a method of manufacturing a plasma display panel according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a plasma display panel.
4A and 4B are a schematic configuration diagram and a cross-sectional view showing a conventional sheet-shaped dielectric material.
FIGS. 5A to 5I are process cross-sectional views illustrating a conventional method for manufacturing a plasma display panel.
6A and 6B are a perspective view and a cross-sectional view showing the main structure of a plasma display panel.
[Explanation of symbols]
1 Front panel
2 Rear panel
3, 7 substrates
4 display electrodes
5, 9 Dielectric layer
8 Address electrode
21 Sheet-like dielectric material
22 Support film
23, 38 Photosensitive dielectric forming material layer
24, 37 Dielectric forming material layer
25 Cover film
31 glass substrate
33 Transparent electrode
36 bus electrodes

Claims (7)

A photosensitive dielectric forming material layer formed on a support film and containing glass powder, a binder resin and a photosensitive resin, and formed on the photosensitive dielectric forming material layer and containing glass powder and a binder resin A decomposition temperature or a combustion temperature or a volatilization temperature of the binder resin contained in the photosensitive dielectric formation material layer is a decomposition temperature of the binder resin of the dielectric formation material layer. Alternatively , a sheet-like dielectric material having a temperature equal to or lower than a combustion temperature or a volatilization temperature .   The sheet-like dielectric material according to claim 1, wherein the photosensitive dielectric material layer and the dielectric material layer contain a solvent.   3. The decomposition temperature or combustion temperature or volatilization temperature of the solvent contained in the photosensitive dielectric forming material layer is equal to or lower than the decomposition temperature, combustion temperature or volatilization temperature of the solvent of the dielectric forming material layer. The sheet-like dielectric material described in 1. A photosensitive dielectric forming material layer containing glass powder, a binder resin and a photosensitive resin, and a dielectric forming material layer formed on the photosensitive dielectric forming material layer and containing glass powder and a binder resin. A transfer step of transferring the provided dielectric material layer and the photosensitive dielectric material layer onto the substrate by superimposing the provided sheet-like dielectric material on the substrate so that the dielectric material layer is on the substrate side; A pattern formation step of exposing and developing the photosensitive dielectric forming material layer using a mask having a predetermined pattern, and then firing the photosensitive dielectric forming material layer and the dielectric forming material layer to form a dielectric layer. And a decomposition temperature or a combustion temperature or a volatilization temperature of the binder resin contained in the photosensitive dielectric forming material layer of the sheet-like dielectric material is a binding temperature of the dielectric forming material layer. Resin minutes Method of manufacturing a plasma display panel, wherein the temperature or is below the combustion temperature or volatilization temperature. By exposing and developing the photosensitive dielectric forming material layer in the pattern forming process, at least one concave portion is formed in the dielectric layer for each light emitting pixel region of the plasma display panel, and the dielectric layer film on the bottom surface of the concave portion is formed. The method of manufacturing a plasma display panel according to claim 4 , wherein the thickness is reduced. The method for manufacturing a plasma display panel according to claim 4 , wherein the photosensitive dielectric forming material layer and the dielectric forming material layer contain a solvent. 6. the decomposition temperature or combustion temperature or volatilization temperature of the solvent contained in the photosensitive dielectric formation material layer, characterized in that it is below the decomposition temperature or combustion temperature or volatilization temperature of the solvent of the dielectric formation material layer A method for producing a plasma display panel as described in 1. above.

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