JPWO2009081490A1 - Phosphor paste - Google Patents

Abstract

A phosphor paste (1) having a high viscosity solvent (first organic compound) (2) and phosphor particles (5) dispersed in the high viscosity solvent (2), the high viscosity solvent (2) Has a terpene skeleton and a viscosity at 25 ° C. of 10,000 to 1,000,000 mPa · s. By using the high viscosity solvent (2), a phosphor paste (1) containing no polymer as a constituent component is obtained. For this reason, the production efficiency of a product (for example, a plasma display panel) using the phosphor paste can be improved.

Description

  The present invention relates to a phosphor paste technology, and more particularly to a technology effective when applied to a phosphor paste used for manufacturing a display device using a phosphor as a light emitting element such as a plasma display.

  A phosphor is an inorganic substance that is excited by irradiation with vacuum ultraviolet rays or the like and emits visible light. For example, in a flat display device such as a plasma display panel (PDP) using the property that a phosphor emits visible light, each color of red (R), green (G), and blue (B) is used. This phosphor is used as a light emitter that emits visible light.

  A phosphor is a substance in a solid state at room temperature (25 ° C.). Therefore, when a predetermined amount of phosphor is applied to a predetermined position, or when it is molded into a predetermined shape, a composition called a phosphor paste in which this powdery phosphor is dispersed in an organic compound is used. .

  Further, when a predetermined amount of the phosphor paste is applied to a predetermined position, or when it is molded into a predetermined shape, the phosphor paste has a predetermined viscosity (thixotropy) depending on the application method or the molding method. Need to be.

  As a method for obtaining this necessary viscosity, there is a technique in which a phosphor paste contains a polymer such as a resin called a binder.

For example, Japanese Unexamined Patent Application Publication No. 2007-145597 (Patent Document 1) discloses a phosphor paste containing phosphor powder, an organic binder resin, and an organic solvent as constituent components.
JP 2007-145973 A

  In order to cause the phosphor to emit light, it is necessary to remove the organic compound after applying the phosphor paste or after forming the phosphor paste into a predetermined shape. In the step of removing the organic compound, a method of heating the phosphor paste to gasify (evaporate) the organic compound component and discharge it out of the phosphor paste system (hereinafter referred to as transpiration) is generally used.

  Among the materials constituting the phosphor paste, an organic solvent used as a solvent for dispersing the phosphor and polymer (polymer) is relatively easy to evaporate. For example, the phosphor paste evaporates by heating to about 150 ° C. (Called the drying process).

  However, polymers used as binders are less likely to evaporate than organic solvents. For example, binder residues may remain in the heated phosphor even when heated to 350 ° C. or higher.

  If the binder residue remains in the heated phosphor, the phosphor may not emit predetermined visible light. Alternatively, the light emission amount may be reduced, and predetermined luminance may not be obtained. Further, when the phosphor is formed in a plurality of regions, if the binder residue varies between the plurality of regions, the amount of light emission varies. For example, when a phosphor is used as a light emitter of a flat display device such as a PDP, the phosphor is formed in discharge spaces (a plurality of spaces) called cells partitioned by barrier ribs, but a binder residue in the phosphor. If there is, the brightness of each discharge space varies.

  In addition, a discharge gas composed of, for example, a rare gas is enclosed in the discharge space. However, when a decomposition gas from the binder is generated, the discharge space is contaminated by the decomposition gas.

  In order to prevent the adverse effects caused by the binder components remaining in the phosphor as described above, a process of completely removing the binder components in the phosphor paste (referred to as a binder removal process) is required.

  Here, as described above, since the polymer constituting the binder is difficult to evaporate, it is generally necessary to heat the phosphor paste to about 450 ° C. (called firing) and hold it for about several tens of minutes to several hours in the binder removal step. There is.

  The method of removing the binder component in the phosphor paste by firing the phosphor paste in the binder removal step has the following problems.

  First, since the processing temperature is high, the energy consumption required for processing is large. Further, since the time required for heating or the time for holding at high temperature is long, the production efficiency is poor. Further, when the phosphor is heated at a high temperature, the phosphor may be oxidized and deteriorated.

  This invention is made | formed in view of the said subject, The objective is to provide the technique which can improve the manufacture efficiency of the products (for example, PDP etc.) which use fluorescent substance paste.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  That is, the present invention is a phosphor paste having a first organic compound and phosphor particles dispersed in the first organic compound, wherein the first organic compound has a terpene skeleton and has a temperature of 25 ° C. Viscosity at 10 to 1,000,000 mPa · s.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  That is, since a predetermined viscosity can be obtained without using a polymer for the phosphor paste, the production efficiency of a product (for example, PDP) using the phosphor paste can be improved.

It is explanatory drawing which shows the manufacture flow of the dielectric paste which is one embodiment of this invention. It is explanatory drawing which shows the temperature dependence of the viscosity of the highly viscous solvent which is one embodiment of this invention, and the amount of evaporation. It is a principal part expansion perspective view which expands and shows the principal part of PDP which is one embodiment of this invention. It is a principal part expanded sectional view which shows the state which accumulated the front structure and back structure shown in FIG.

  Components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted in principle. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
<Method for producing phosphor paste>
First, the manufacturing method of the phosphor paste 1 of this Embodiment is demonstrated using FIG. FIG. 1 is an explanatory diagram showing a manufacturing flow of the phosphor paste of the present embodiment.

  First, a high-viscosity solvent (first organic compound) 2 and a solvent (second organic compound, dispersant) 3 shown in FIG. 1 are prepared and mixed.

  The high-viscosity solvent 2 is a solvent that is mixed in order to give the phosphor paste 1 a predetermined viscosity. In general, a polymer (polymer, polymer organic compound) such as ethyl cellulose or acrylic resin is used to give a predetermined viscosity to the phosphor paste, but the phosphor paste 1 of the present embodiment has a high viscosity. Since the solvent 2 is used, a polymer such as a resin is not included as a constituent component. The high viscosity solvent 2 is liquid at 25 ° C.

  On the other hand, the solvent 3 is used as a dilution solvent for adjusting the viscosity of the phosphor paste 1, and it is preferable to use a material having a lower viscosity at 25 ° C. than the high-viscosity solvent 2 described later. The solvent 3 does not contain a polymer (polymer, polymer organic compound) as a constituent component.

  Examples of such materials include aromatic hydrocarbon compounds such as toluene and xylene, ether compounds such as tetrahydrofuran and 1,2-dibutoxyethane, ketone compounds such as acetone and methyl ethyl ketone, ethyl acetate, butyl acetate, and acetic acid 2- Ester compounds such as (2-butoxyethoxy) ethyl and dioctyl phthalate, alcohol compounds such as isopropyl alcohol, 2- (2-butoxyethoxy) ethyl alcohol, terpineol and 2-phenoxyethanol, BC (butyl carbitol), BCA (butyl) Carbitol acetate).

  The viscosity of the phosphor paste 1 is mainly defined by the blending ratio of the high viscosity solvent 2 and the solvent 3. That is, the phosphor paste 1 of the present embodiment uses the high-viscosity solvent 2 to obtain a predetermined viscosity characteristic without including a polymer used as a thickener (binder) in a general phosphor paste. Can do.

  Here, the predetermined viscosity characteristic of the phosphor paste 1 is a viscosity characteristic required when the phosphor paste 1 is subjected to processing (for example, applied to a substrate), and the value varies depending on the processing means. In detail, it explains in full detail when demonstrating the manufacturing method of PDP which is the usage example of the fluorescent substance paste 1 of this Embodiment.

  Since the high-viscosity solvent 2 functions as a thickener for the phosphor paste 1, if the viscosity at a temperature (for example, 25 ° C.) when the phosphor paste 1 is subjected to processing (for example, applied to a substrate) is too low, fluorescence The body paste 1 cannot obtain a predetermined viscosity. Moreover, when a viscosity is too high, the printability at the time of using the fluorescent substance paste 1 as a printing agent will worsen.

  As a result of studies by the present inventors, it is preferable to use a high viscosity solvent 2 having a viscosity characteristic within a range of 10,000 to 1,000,000 mPa · s at 25 ° C.

  Almost no organic polymer-containing material having the above-mentioned viscosity characteristics is known. However, as a result of investigation by the present inventors, it has been found that the following materials can be applied as the high-viscosity solvent 2. That is, an organic compound (isobornylcyclohexanol) having a terpene skeleton represented by the following structural formula (1) can be used.

  The organic compound (isobornylcyclohexanol) represented by the structural formula (1) is not a polymer, but has a viscosity in the range of 10,000 to 1,000,000 mPa · s at 25 ° C. Specifically, the one with 336000 mPa · s at 25 ° C. and 65500 mPa · s at 30 ° C. was used.

  In addition, isobornylcyclohexanol has the following physical properties. The physical characteristics of isobornylcyclohexanol used for the high-viscosity solvent 2 will be described with reference to FIG. FIG. 2 is an explanatory diagram showing the temperature dependence of the viscosity and the evaporation amount of the high-viscosity solvent 2 of the present embodiment.

  In FIG. 2, the horizontal axis represents the temperature (° C.) of the high viscosity solvent 2, the first vertical axis (left vertical axis in FIG. 2) represents the viscosity of the high viscosity solvent 2, and the second vertical axis (right side in FIG. 2). The vertical axis) shows the evaporation amount of the high viscosity solvent 2.

  As shown in FIG. 2, when the high-viscosity solvent 2 is heated from 25 ° C., the viscosity rapidly decreases, and when heated to 40 ° C., it becomes 1/10 or less of the viscosity at 25 ° C. Moreover, the temperature curve of the viscosity has a displacement point in the vicinity of about 40 ° C., and even when the high viscosity solvent 2 is heated to 40 ° C. or higher, the viscosity does not decrease greatly. On the other hand, the evaporation amount hardly evaporates even when the high-viscosity solvent 2 is heated to 70 ° C., but this temperature curve has a displacement point at a point exceeding about 70 ° C., and the evaporation amount exceeds 70 ° C. Will increase.

  In the present embodiment, the high viscosity solvent 2 is heated in the range of 40 ° C. to 70 ° C. before mixing the solvent 3 and the high viscosity solvent 2 shown in FIG. To do. By heating the high-viscosity solvent in the range of 40 ° C. to 70 ° C., the viscosity can be reduced while suppressing the evaporation of the high-viscosity solvent 2, so that the high-viscosity solvent can be easily obtained with an extremely simple mixing device. 2 and the solvent 3 can be mixed uniformly.

  That is, the production efficiency of the phosphor paste 1 can be improved. As a mixing device of the high-viscosity solvent 2 and the solvent 3, for example, a stirring and mixing device such as a homomixer can be used. By this mixing step, a vehicle 4 that is a mixed solution of the high-viscosity solvent 2 and the solvent 3 is obtained.

  Next, the phosphor particles 5 shown in FIG. 1 are prepared and dispersed in the vehicle 4. The phosphor particles are prepared as powder particles (inorganic particles) so as to be easily dispersed in the vehicle 4. In addition, since the vehicle 4 can maintain a state of reduced viscosity in the range of 40 ° C. to 70 ° C., the phosphor particles 5 can be easily and uniformly dispersed with an extremely simple mixing device. As a mixing apparatus used in this dispersion step, for example, a mixing apparatus such as a homomixer can be used.

  The phosphor particles 5 can be variously selected according to the use of the phosphor paste 1. For example, when the phosphor paste 1 is used for forming a light emitting element of a color display device such as a PDP, the color display device displays a color image by combining each color of red (R), green (G), and blue (B). Therefore, three types of phosphor particles 5 that emit R, G, and B light are prepared.

  In the case of PDP, a method is used in which phosphors are excited by vacuum ultraviolet rays having a predetermined wavelength (for example, 147 nm) to emit light of R, G, and B colors. It is preferable to select a material having good light color and luminous efficiency. Examples of such a material include the following materials, but the material of the phosphor particles 5 is not limited to the following.

For example, [(Y, Gd) BO ₃ : Eu ³⁺ ] for the phosphor particles 5 for red, [Zn ₂ SiO ₄ : Mn ²⁺ ] for green, [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] for blue, etc. Can be used.

  By this dispersion step, the phosphor particles 5 are dispersed in the high viscosity solvent 2.

  Next, the vehicle 4 in which the phosphor particles 5 are dispersed is filtered. By performing this filtration step, impurities contained in the vehicle 4 and phosphor particles 5 larger than a predetermined particle diameter can be removed. Therefore, the phosphor paste 1 after the filtration step is completed is in a state where the phosphor particles 5 are uniformly dispersed in the vehicle 4 (that is, in the high-viscosity solvent 2 and the solvent 3).

  Finally, for example, the phosphor paste 1 is obtained by cooling by leaving it in an atmosphere of 25 ° C.

  By the way, in this Embodiment, the structural example in which the high viscosity solvent 2 and the solvent 3 were contained as an organic compound component contained in the fluorescent substance paste 1 was demonstrated. However, when isobornylcyclohexanol is used as the high-viscosity solvent 2, as described above, the viscosity decreases when heated to 40 ° C. or higher. Therefore, the phosphor paste 1 containing only the high-viscosity solvent 2 as an organic compound component is used. You can also.

  However, when isobornylcyclohexanol is used as the high-viscosity solvent 2, the viscosity varies greatly depending on the temperature in a temperature range lower than 40 ° C. as shown in FIG. For this reason, when the organic compound component contained in the phosphor paste 1 is only the high-viscosity solvent 2, the temperature range (for example, 20 ° C. to 30 ° C.) when the phosphor paste 1 is subjected to processing (for example, applied to a substrate). ), The viscosity of the phosphor paste 1 may change greatly.

  Therefore, as shown in FIG. 1, the phosphor paste in a temperature zone (for example, 20 ° C. to 30 ° C.) when the phosphor paste 1 is subjected to processing by adding the solvent 3 as a diluent solvent to the high viscosity solvent 2. It is preferable to suppress the viscosity change of 1.

  Moreover, it is preferable to use the solvent 3 whose viscosity change rate by the temperature in 20 to 30 degreeC which is a temperature range at the time of using the phosphor paste 1 for processing is smaller than the high-viscosity solvent 2. Each of the materials described above as an example of the solvent 3 has a viscosity change with temperature in the range of 20 ° C. to 30 ° C. smaller than the viscosity change rate of isobornylcyclohexanol, which is the high viscosity solvent 2.

  By using such a material as the solvent 3, it is possible to suppress a change in viscosity during processing of the phosphor paste 1. For this reason, the workability of the phosphor paste 1 can be improved and the production efficiency can be improved.

  Although the ratio of each structural component contained in the phosphor paste 1 varies depending on the required viscosity, in the present embodiment, the following was created as an example of the phosphor paste 1. That is, the weight ratio with respect to the phosphor paste 1 was 30 wt% for the phosphor particles 5, 16 wt% for the solvent 3, and 54 wt% for the high viscosity solvent 2. The overall viscosity of the phosphor paste 1 was 25,000 mPa · s at 25 ° C.

  In the present embodiment, the method of dispersing the phosphor particles 5 in the vehicle 4 has been described, but the order of the mixing step and the dispersing step is not limited to this.

  For example, the phosphor particles 5 may be dispersed in the solvent 3 to prepare a slurry, and the high viscosity solvent 2 heated in the range of 40 ° C. to 70 ° C. may be mixed therewith. Or it is good also as a method which disperse | distributes the fluorescent substance particle 5 in the high-viscosity solvent 2 heated in the range of 40 to 70 degreeC, makes a slurry, and mixes the solvent 3 with this.

  Whichever method is used, the phosphor paste 1 in which the phosphor particles 5 are dispersed in the solvent 3 and the high-viscosity solvent 2 is obtained in the same manner as the method shown in FIG.

<PDP structure>
Next, an example of the structure of a PDP that is an application example of the phosphor paste 1 of the present embodiment will be described using an AC surface discharge type PDP as an example with reference to FIGS. FIG. 3 is an enlarged perspective view of a main part showing an enlarged main part of the PDP of the present embodiment, and FIG. 4 is an enlarged cross-sectional view of the main part showing a state in which the front structure and the back structure shown in FIG. is there. Note that FIG. 3 shows a state in which the front structure and the back structure are separated from each other by a predetermined distance in order to facilitate explanation of the structure of the PDP.

  In FIG. 3, the PDP 10 has a front structure (first structure) 11 and a back structure (second structure) 12. The front structure 11 and the back structure 12 are combined in a state of facing each other.

  The front structure 11 has a display surface of the PDP 10, and has a front substrate (substrate, first substrate) 13 mainly made of glass on the display surface side. A plurality of X electrodes (electrodes, first electrodes) 14 and Y electrodes (electrodes, first electrodes) 15 for performing sustain discharge are formed on the surface of the front substrate 13 opposite to the display surface.

  The X electrode 14 and the Y electrode 15 are formed on the display surface side of the PDP 10. Therefore, for example, an X transparent electrode 14a and a Y transparent electrode 14b made of a transparent electrode material such as ITO (Indium Tin Oxide), and an X bus electrode 14b and a Y bus electrode electrically connected to each transparent electrode. 15b.

  The X bus electrode 14b and the Y bus electrode 15b are formed to reduce the electric resistance of the X electrode 14 and the Y electrode 15, and are formed of Cu, Ag, or the like having a lower electric resistance than the transparent electrode.

  The X electrode 14 and the Y electrode 15 are formed so as to extend along the lateral (row) direction. In FIG. 3, the X transparent electrode 14 a and the Y transparent electrode 15 a are in the shape of a band extending in the lateral direction, but are not limited to this shape, and various modifications exist. For example, a structure may be adopted in which the distance between the X electrode 14 and the Y electrode 15 is locally reduced corresponding to the position of a discharge space described later for the purpose of improving the discharge efficiency of the sustain discharge.

  The X electrode 14 and the Y electrode 15 are arranged at predetermined arrangement intervals in the longitudinal (column) direction intersecting with the extending direction. Moreover, it arrange | positions so that the pair of the adjacent X electrode 14 and Y electrode 15 may be made. For example, the X electrodes 14 and the Y electrodes 15 are alternately arranged. In the PDP 10, a pair of X electrodes 14 and Y electrodes 15 form a display row.

  These electrode groups (X electrode 14 and Y electrode 15) are covered with a dielectric layer 17. A protective layer (metal oxide layer) 18 made of a metal oxide such as MgO is formed on the surface of the dielectric layer 17. The protective layer 18 is formed so as to cover one surface of the dielectric layer 17.

  The material used for the protective layer 18 is not limited to a single component of MgO. For example, a composite material in which CaO (calcium oxide) is mixed with MgO may be used. By mixing CaO, the sputtering resistance of the protective layer 18 can be improved.

  On the other hand, the back structure 12 has a back substrate (substrate, second substrate) 19 mainly made of glass. A plurality of address electrodes (electrodes, second electrodes) 20 are formed on the back substrate 19. Each address electrode 20 is formed so as to extend in a vertical (column) direction intersecting (substantially at right angles) with a direction in which the X electrode 14 and the Y electrode 15 extend. The address electrodes 20 are arranged with a predetermined arrangement interval so as to be along (substantially parallel) with each other.

  The address electrode 20 is covered with a dielectric layer 21. A plurality of partition walls 22 extending in the thickness direction of the back structure 12 are formed on the dielectric layer 21. The barrier ribs 22 are formed to extend in a line along the direction in which the address electrodes 20 extend. Further, the position of the partition wall 22 on the plane is arranged between the adjacent address electrodes 20. By disposing the barrier ribs 22 between the adjacent address electrodes 20, a space for dividing the surface of the dielectric layer 21 in the column direction corresponding to the position of each address electrode is formed.

  In addition, the top surface of the dielectric layer 21 on the address electrode 20 and the side surface of the partition wall 22 are excited by vacuum ultraviolet rays to generate visible light of each color of red (R), green (G), and blue (B). The bodies 23r, 23g, and 23b are respectively formed at predetermined positions.

  In the PDP 10, one cell is configured corresponding to the intersection of the pair of X electrode 14, Y electrode 15, and address electrode 20. Each cell is formed with either a red phosphor 23r, a green phosphor 23g, or a blue phosphor 23b. A set of R, G, B cells constitutes a pixel. That is, each of the phosphors 23r, 23g, and 23b is a light-emitting element of the PDP 10, and is excited by vacuum ultraviolet rays having a predetermined wavelength generated by discharge to emit visible light of each color of red (R), green (G), and blue (B). appear.

  Here, each of the phosphors 23r, 23g, and 23b is formed using the phosphor paste 1 of the present embodiment. The effects obtained by using the phosphor paste 1 for forming the phosphor 23 will be described in detail when the method for manufacturing the PDP 10 is described.

  Next, as shown in FIG. 4, the front structure 11 and the back structure 12 are fixed in a state where the surface on which the protective layer 18 is formed and the surface on which the partition wall 22 is formed face each other. The protective layer 18 and the partition wall 22 are fixed in a state where at least a part thereof is in contact. The distance between the front structure 11 and the back structure 12 is defined by the partition wall 22, and the distance is, for example, about 100 μm.

  By fixing the protective layer 18 and the barrier rib 22 in contact with each other, a discharge space 24 partitioned by the protective layer 18 and the barrier rib 22 is formed, and the surface of the discharge space 24 on the back structure 12 side (the bottom surface and both sides). The surface) is in a state where the phosphor 23 is formed. The peripheral portion of the PDP 10 is sealed with a sealing agent (not shown) such as a low-melting glass material called frit, and a gas called a discharge gas (for example, a mixture of Ne and Xe) is formed in the discharge space 24. Gas) is sealed at a predetermined pressure.

  The PDP 10 has a structure in which a discharge is generated for each cell in the discharge space 24 and the R, G, and B phosphors 23 are excited and emitted by vacuum ultraviolet rays generated by the discharge.

  By the way, although various structures exist according to required performance, a drive system, etc., PDP10 is not limited to the structure shown in FIG.3 and FIG.4 of this Embodiment. For example, FIG. 3 illustrates an example in which the discharge space is partitioned by the barrier ribs 22 extending in a line shape (vertical direction).

  However, for the purpose of improving luminance, the discharge space may be partitioned by barrier ribs arranged in a grid pattern. The PDP 10 of the present embodiment can also take such a configuration.

<Method for producing PDP 10>
Next, a method for manufacturing PDP 10 of the present embodiment will be described with reference to FIGS.

  (A) First, the front structure 11 (where the protective layer 18 is not formed) and the planar structure 12 shown in FIG. 3 are prepared. The front structure 11 prepared in this preparation process is manufactured as follows, for example.

  First, the front substrate 13 is prepared, and the X electrode 14 and the Y electrode 15 are formed in a predetermined pattern on one surface. In addition, bus electrodes 16 are formed on the X electrode 14 and the Y electrode 15, respectively. Next, a dielectric layer 17 is formed on the front substrate 13 so as to cover the X electrode 14, the Y electrode 15, and the bus electrode 16. At this stage, the protective layer 18 shown in FIG. 1 is not formed on the front structure 11.

  Moreover, the back structure 12 shown in FIG. 3 is manufactured as follows, for example.

  (A) First, the back substrate 19 shown in FIG. 3 is prepared (substrate preparation process).

  (B) Next, a plurality of address electrodes 20 are formed on the surface of the back substrate 19.

  (C) Next, a dielectric layer 21 is formed so as to cover the address electrodes 20.

  (D) After the dielectric layer 21 is formed, the barrier rib 22 that defines the discharge space is formed on the surface of the dielectric layer 21. The barrier ribs 22 are formed so as to extend along the address electrodes 20. The partition wall 22 can be formed by, for example, a sand blast method.

  (E) Next, predetermined phosphors 23r, 23g, and 23b are formed in each of a plurality of spaces (bottom surface and side walls) partitioned by the partition walls 22. In this phosphor forming step, it is formed by the following method.

  (E1) First, the phosphor paste 1 (see FIG. 1) of the present embodiment is applied to a plurality of spaces (bottom surface and side walls) partitioned by the partition walls 22. As a coating method of the phosphor paste 1, a screen printing method or a dispensing method (nozzle filling method) can be used.

  When the phosphor paste 1 is applied by screen printing, the phosphor paste 1 passes through the screen mesh, suppresses dripping after application, and is applied to each space partitioned by the partition walls 22. It is sufficient that the film has a viscosity enough to maintain the shape. As a result of studies by the present inventors, such a condition is satisfied if the viscosity of the phosphor paste 1 is in the range of 15,000 to 120,000 mPa · s.

  In addition, when applying the phosphor paste 1 by the dispensing method, an appropriate amount can be discharged from the discharge nozzle of the dispenser, the liquid dripping after application is suppressed, and the phosphor paste 1 is applied to each space partitioned by the partition walls 22. It is sufficient that the film of the phosphor paste 1 has a viscosity that can maintain the shape. As a result of studies by the present inventors, as in the case of the screen printing method, such a condition is satisfied if the viscosity of the phosphor paste 1 is in the range of 15,000 to 120,000 mPa · s.

  (E2) Next, the phosphor paste 1 is heated to remove organic compound components (solvent 3 and high-viscosity solvent 2) contained in the phosphor paste 1. Moreover, in this heating process, it heats to the melting | fusing point of the inorganic particle component (phosphor particle 5) contained in the phosphor paste 1, and fuses and integrates it.

  Here, when a polymer is contained in the phosphor paste, the polymer is gasified after being decomposed into monomers. For this reason, in order to gasify all the organic compound components, much heat energy is required. Further, if a part of the phosphor particles 5 is melted and integrated before all the organic compound components are gasified, the organic compound components (particularly polymers) may remain as residues in the phosphor 23.

  For this reason, in the case of using a phosphor paste containing a polymer, generally, a process for removing the polymer from the gas by removing it from the melting point of the phosphor particles for a predetermined time (debinding process) is required. Even when this binder removal step is performed, when the temperature at which the polymer is completely gasified and the temperature at which the phosphor particles 5 are integrated are close to each other, a part of the organic compound component may remain as a residue on the phosphor 23.

  However, since the phosphor paste 1 of the present embodiment does not contain a polymer as an organic compound component, the thermal energy required to gasify the organic compound component is lower than that of a phosphor paste containing a polymer. This is because a process for decomposing the polymer into monomers is not necessary.

  Of the organic chemical components constituting the phosphor paste 1, the high viscosity solvent 2 requires more heat energy to evaporate than the solvent 3, and this high viscosity solvent 2 is also shown in FIG. It can be evaporated by heating to 70 ° C. or higher. Moreover, it becomes easier to evaporate by raising the temperature.

  Therefore, since the phosphor paste 1 does not contain a polymer as an organic compound component, the organic compound component can be easily removed. For example, after the phosphor paste 1 is applied, even if the phosphor particles 5 are linearly heated to a temperature at which the phosphor particles 5 are melted and integrated (for example, 230 ° C.), before the phosphor particles 5 are integrated, Organic compound components can be completely removed.

  That is, since the binder removal step can be omitted, the manufacturing efficiency can be greatly improved.

  In addition, the phosphor particles 5 may be held for several tens of minutes at a lower temperature (for example, 200 ° C.) rather than being linearly heated to a temperature at which the phosphor particles 5 are melted and integrated. In this case, the possibility that the residue of the organic compound component remains in the phosphor 23 can be reliably prevented.

  Even in this case, it is not necessary to take time to decompose the polymer into the monomer, so that the holding time can be greatly shortened.

  Since the phosphor 23 provided in the PDP 10 of the present embodiment is formed using the phosphor paste 1, the organic compound component can be completely removed. For this reason, since generation | occurrence | production of the decomposition gas resulting from the residue of an organic compound component can be prevented, the reliability of PDP10 can be improved. When this heating step is completed, the back structure 12 shown in FIG. 3 is obtained.

  (B) Next, as a protective layer forming step, the protective layer 18 is formed on the surface of the dielectric layer 17 of the front structure 11. The protective layer 18 is made of, for example, MgO, and can be formed by, for example, a vapor deposition method. In the present embodiment, a protective layer 18 of MgO having a thickness of 1 μm is formed on the surface of the dielectric layer 17 by a vacuum evaporation method using an electron beam using an MgO source as a target.

  Here, the metal oxide such as MgO constituting the protective layer 18 has a property of easily adsorbing moisture in the atmosphere. For this reason, this protective layer forming step is preferably performed in a vacuum (reduced pressure) atmosphere to prevent or suppress the adhesion of moisture to the protective layer 18.

  (C) Next, the back structure 12 and the front structure 11 are assembled. The assembly process is performed as follows, for example.

  First, as an alignment process, alignment is performed so that the front structure 11 and the back structure 12 have a predetermined positional relationship. In the alignment step, high-precision fine adjustment is performed so that the X electrodes 14 and Y electrodes 15 of the front structure 11 and the address electrodes 20 of the back structure 12 have a predetermined positional relationship.

  Next, as a sealing step, as shown in FIG. 4, the surface of the front structure 11 on which the protective layer 18 is formed and the surface of the back structure 12 on which the partition wall 22 is formed are overlapped, The periphery of the region where the front structure 11 and the back structure 12 overlap is sealed with a sealing agent (not shown) such as a low melting glass material called frit. When this sealing step is completed, the front structure 11 and the back structure 12 are fixed while maintaining a predetermined positional relationship.

  The sealing agent is in close contact with the front structure 11 and the back structure 12, respectively, and seals the periphery of both structures. As a result, the discharge space 24 shown in FIG. 4 is blocked from the outside of the PDP 10 (however, the internal gas formed at one or more locations of the front structure 11 or the back structure 12 is exhausted and the discharge gas is sealed). Vents are secured).

  Therefore, it is preferable that the sealing process is performed in a vacuum (reduced pressure) atmosphere in order to prevent the protective layer 18 from adsorbing impurities such as moisture.

  Next, as a discharge gas introduction step, a rare gas or the like is introduced into the discharge space 24 through a ventilation path connected to a ventilation hole (not shown) formed in one or more locations of the front structure 11 or the back structure 12. A predetermined discharge gas (for example, a mixed gas of Ne and Xe) is introduced. Before introducing the discharge gas, the remaining gas in the discharge space 24 is exhausted in advance.

  Finally, the opening of the vent hole is sealed in a sealing step, and the PDP 10 is completed.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment of the invention, and various modifications can be made without departing from the scope of the invention. is there.

  For example, although the PDP 10 has been described as an application example of the phosphor paste 1, a PDP module may be obtained by attaching a circuit board on which a circuit such as a drive circuit is formed to the PDP. Needless to say, a housing such as a cover or a support member such as a stand may be attached to the PDP module and incorporated in the PDP apparatus.

  The present invention can be applied to a PDP, a PDP module in which various circuit boards such as a drive circuit are attached to the PDP, or a PDP apparatus in which a cover or a support member is attached to the PDP module.

Claims (5)

A first organic compound;
Phosphor particles dispersed in the first organic compound,
The first organic compound is
A phosphor paste having a terpene skeleton and a viscosity at 25 ° C. of 10,000 to 1,000,000 mPa · s. The phosphor paste according to claim 1,
The phosphor paste has a second organic compound whose viscosity at 25 ° C. is lower than that of the first organic compound. In the phosphor paste according to claim 2,
The phosphor paste, wherein the second organic compound has a lower rate of change in viscosity due to temperature at 20 ° C. to 30 ° C. than the first organic compound. The phosphor paste according to claim 1,
The phosphor paste, wherein the first organic compound is an organic compound represented by the following structural formula (1).
The phosphor paste according to claim 1,
The phosphor paste is used for forming a phosphor that is a light emitting element of a plasma display panel.