JP2007294223A - Manufacturing method of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a plasma display panel wherein materials can be used without wasting them, and a phosphor layer can be highly precisely formed. <P>SOLUTION: This manufacturing method has a first process 1 to fill wax particles in which phosphors are dispersed in wax in a plurality of discharge cells 4, a process 2 to fix the phosphors in the discharge cells 4 by solidifying the wax particles after heating and dissolving the wax particles in the discharge cells 4 by irradiating laser to prescribed discharge cells 4 among a plurality of the discharge cells 4 filled with the wax particles, and a process 3 to remove the wax particles filled in the discharge cells 4 other than the prescribed discharge cells 4 in this order, and also has a process 4 to make the phosphor layer by fixing the phosphor to the inner wall of the discharge cell 4 by evaporating the wax in the discharge cell 4 after repeating the process 1-3 for every color of the phosphor dispersed in the wax particles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a plasma display panel, in which a phosphor layer is formed on the inner wall of a discharge cell partitioned by barrier ribs in a plasma display panel (PDP).

  Conventionally, various methods have been proposed as a method for manufacturing a plasma display panel used as a display device such as a television, and among these, a screen printing method has become the mainstream. This screen printing method is a method in which a phosphor layer is formed on a discharge cell partitioned by barrier ribs in a PDP using a wall surface coating method.

  The screen printing method is a method in which a paste-like liquid mixed with a phosphor is poured into a predetermined space, that is, a predetermined discharge cell, using a printing method via a screen. The screen printing method utilizes a mechanism in which a phosphor layer is naturally formed on the wall surface in the discharge cell by surface tension during drying.

  However, such a screen printing method has a problem that, when the patterns are superimposed on the printing position to be printed, the printing misalignment increases as the printing area increases, so that the printing alignment accuracy is low. For this reason, when the phosphor layer is formed in the discharge cell of the PDP by using the screen printing method, for example, a displacement of 50 to 200 μm is caused with respect to a 1 m length, and distortion is also generated.

  In addition, as another method of manufacturing a PDP, red (R) and green are discharged by discharging a phosphor slurry in which phosphors are dispersed into individual discharge cells partitioned by barrier ribs using a microdispenser. A method of separately coating phosphors of the three primary colors (G) and blue (B) is conceivable. However, when this method is used to discharge a phosphor toward the discharge cell of a PDP having a fine pattern, there is a possibility that problems such as clogging of phosphor particles in the discharge cell may occur.

  In order to solve the problems such as the above-described misalignment in forming the phosphor layer and clogging of the phosphor as described above, patterning is performed by photolithography using a mask for selecting a discharge cell into which the phosphor is injected. A method has been proposed in which a phosphor layer is formed in a predetermined discharge cell partitioned by barrier ribs using a thin film (for example, Patent Document 1).

Further, a phosphor is mixed with a film-like sheet used in Patent Document 1 to form a photosensitive flexible film-like sheet, and this film-like sheet is laminated under pressure and decompression to be exposed and developed. Thus, a method of forming a phosphor layer in the discharge cell has also been proposed.
JP 2000-57948 A

However, both of the production method described in Patent Document 1 and the production method of exposing and developing the photosensitive film-like sheet have the following problems.
(1) Material use efficiency such as phosphor is low and loss is large.
(2) When forming each color phosphor layer in the discharge cell, it is difficult to make the alignment appropriate.
(3) It is difficult to efficiently inject the slurry in which the phosphor is dispersed into the discharge cell having high definition.

  The present invention has been made in view of the above circumstances, and it is possible to use the material without waste, and to improve the alignment accuracy with respect to the discharge cell and to form a phosphor layer with high accuracy. An object of the present invention is to provide a method for manufacturing a display panel.

As a result of intensive studies to solve the above problems, the present inventors have focused on the following points.
(1) Use laser technology with high processing accuracy.
(2) Use an expensive phosphor material in a cycle.
(3) The thermal characteristics and organic physical characteristics of each material used for forming the phosphor layer are fully utilized.
(4) The phosphor is dispersed in wax and used as composite particles.
(5) It can be processed at high speed, and can be manufactured at low cost with little material loss.

  As a material having the above characteristics, it is a material that is heated and melted by laser irradiation, becomes a liquid when heated, has a surface tension necessary for coating the inner wall of the discharge cell, and easily fills the discharge cell. The present invention was completed by using wax particles having a shape characteristic capable of being dispersed and phosphors dispersed in wax.

  By using the wax particles as described above, the phosphor dispersed in the wax can be filled in a necessary amount in a necessary discharge cell. Further, when the phosphor is fixed in the discharge cell in a predetermined arrangement pattern, the property that the wax particles are heated and melted can be used. Also, as a method of heating the wax particles, a heating method using laser irradiation that can output a variable, narrow the beam spot diameter, and can be positioned and scanned at high speed should be used. It is particularly effective to use a carbon dioxide laser.

  Using such a method for forming the phosphor layer in the discharge cell with high accuracy is extremely significant in terms of industrial production, such as shortening the process time, reducing the manufacturing cost, and improving the yield. In terms of usage efficiency, waste due to disposal of materials can be eliminated, which is a very significant invention.

  That is, the method for manufacturing a plasma display panel according to the present invention is a method for manufacturing a plasma display panel in which phosphor layers are formed on the inner walls of a plurality of discharge cells partitioned by barrier ribs provided on a substrate. Step (1) filling the plurality of discharge cells with wax particles in which any one of the phosphors of the three primary colors of green (G) and blue (B) is dispersed in wax. Next, among the plurality of discharge cells filled with the wax particles, a predetermined discharge cell is irradiated with a laser to heat and melt the wax particles in the discharge cell, and then solidify and discharge the phosphor. A step (2) for fixing in the cell and a step (3) for removing wax particles filled in the discharge cells other than the predetermined discharge cell are sequentially provided, and the steps (1) to (3) Then, after repeating for each color of the three primary color phosphors dispersed in the wax particles, the wax in the discharge cell is evaporated, and the phosphor is fixed to the inner wall of the discharge cell. A step (4) for forming a phosphor layer is provided.

  Moreover, the manufacturing method of the plasma display panel of this invention can be set as the structure which reuses the wax particle removed in the said process (3) in the said process (1).

  In the method of manufacturing a plasma display panel according to the present invention, the laser can be a carbon dioxide laser.

  In the method for producing a plasma display panel of the present invention, the wax may be composed of a waxy substance that is an organic substance having a melting point of 40 to 200 ° C. and that is heated and melted by the transmission wavelength of the laser. .

  In the method for producing a plasma display panel of the present invention, the wax has a melting point of more than 45 ° C., and the main component is at least one of behenyl alcohol, stearyl alcohol, and palmityl alcohol, or a mixture of two or more. Composition.

According to the method for manufacturing a plasma display panel of the present invention, the above configuration improves the alignment accuracy when forming the phosphor layer in the discharge cell, and the phosphor layer is uniform in the entire discharge cell of the plasma display panel. It can be a shape. Further, since components other than the phosphor are evaporated and completely burned by heating, it is possible to prevent impurities from being mixed into the phosphor layer. Thereby, the light emission characteristics of the discharge cell are enhanced.
In the present invention, by using a laser, it is possible to irradiate and heat wax particles by high-speed scanning. Thereby, the process time can be shortened, and the phosphor pattern formation in the entire discharge cell can be performed while aligning more accurately, thereby enabling the phosphor pattern formation with higher accuracy.
In addition, according to the manufacturing method of the present invention, by adopting a method incorporating a cycle process in which the phosphor removed from the discharge cell in the manufacturing process is repeatedly used, the material can be used efficiently and the manufacturing cost can be reduced. It becomes possible to do.
Therefore, a plasma display panel having excellent display characteristics can be manufactured at a low cost.

Hereinafter, the manufacturing method of the plasma display panel of this invention is demonstrated, referring FIGS. 1-5 suitably.
1-5 is a figure explaining one Embodiment of the manufacturing method of the plasma display panel of this invention, and has shown the flow of the process of forming a fluorescent substance layer in a discharge cell.

The method of manufacturing a plasma display panel according to the present invention is a plasma display in which a phosphor layer is formed on the inner walls of a plurality of discharge cells 4 (4a, 4b, 4c, 4d) partitioned by barrier ribs 3 provided on a substrate 2. In the panel manufacturing method, wax particles 5 (5R, 5R, 5R, 5R, 5G, 5D, 5D, 5D, 5D, 5D, and 5B are formed by dispersing phosphors of any one of the three primary colors of red (R), green (G), and blue (B) 5G, 5B) is filled in the plurality of discharge cells 4, and then, a predetermined discharge cell 4 among the plurality of discharge cells 4 filled with the wax particles 5 is irradiated with a laser for discharge. Step (2) of fixing the phosphor in the discharge cell 4 by solidifying the wax particles 5 in the cell 4 by heating and melting, and then filling in the discharge cells 4 other than the predetermined discharge cell 4 Excluded wax particles 5 Step (3) in order, and the steps (1) to (3) are repeated for each of the three primary color phosphors dispersed in the wax particles 5, and then the discharge cell 4 The inside wax is evaporated and the phosphor is fixed to the inner wall of the discharge cell 4 to form a phosphor layer R1, R2, G1, G2, B1, B2 (4).
Hereinafter, each step will be described in detail.

[Step (1)]
In step (1) of the manufacturing method of this embodiment, one of the three primary color phosphors of red (R), green (G), and blue (B) is dispersed in the wax. This is a step of filling the plurality of discharge cells 4 with the wax particles 5 to be sequentially for each of the three primary colors.

First, as shown in FIG. 1, a rib-shaped partition wall 3 made of an insulating material is formed in a grid pattern at a predetermined interval on a flat substrate 2 made of glass, for example, and is discharged by these partition walls 3. A substrate having cells 4 (4a, 4b, 4c, 4d) is prepared.
The dimensions of the discharge cell 4 are determined by the dimensions of the barrier ribs 3 and the intervals at which the barrier ribs 3 are arranged on the substrate 2. For example, the height from the surface of the substrate 2 is 120 to 130 μm and the width is 250 μm in plan view. Space.

"Wax particles"
Next, wax particles as described below are prepared.
The wax particles of the present embodiment are formed by dispersing any one of the three primary color phosphors of red (R), green (G), and blue (B) in the wax.
The wax particles according to the present invention are formed by being dispersed in wax particles such as composite particles, which are blocked by a predetermined diaphragm or the like, or phosphor particles are encapsulated with wax components. is there.

The wax particles according to the present invention preferably have a particle size in the range of 10 to 80 μm.
When the particle size of the wax particles is less than 10 μm and 80 μm or more, the number of phosphors dispersed inside decreases, the number of phosphors fixed in the discharge cell 4 decreases, and sufficient emission characteristics can be obtained. There is a possibility that the phosphor layer cannot be formed. In addition, wax particles of less than 10 μm may adhere to the partition walls in the discharge cell, making it difficult to remove the wax particles in the step (3) described later.
Further, when the particle size of the wax particles exceeds 80 μm, as described above, the discharge cell 4 has a width of about 250 μm, so that the number of wax particles themselves filled in the discharge cell 4 decreases, and the discharge cell 4 is discharged. There is a possibility that the phosphor fixed in the cell 4 is reduced, and a phosphor layer capable of obtaining sufficient light emission characteristics cannot be formed.

As the phosphor, a phosphor usually used in a plasma display panel can be used without any particular limitation.
The material of the phosphor is, for example, (Y, Gd) BO ₃ : Eu ³⁺ for red (R) phosphor, Zn ₂ SiO ₄ : Mn or BaAl ₁₂ O ₁₉ : Mn for green (G),
As the blue (B), BaMgAl ₁₄ O ₂₃ : Eu ²⁺ or the like can be used.
The particle size of the phosphor is preferably about 5 μm, for example. With this particle size, more phosphor can be dispersed in the wax particles having the above particle size.

  In the wax particles according to the present invention, the component used as the wax for dispersing the phosphor in the inside is not particularly limited, but is an organic substance having a melting point of 40 to 200 ° C., and is heated and melted by a laser transmission wavelength as described later. It is preferable to use a waxy substance. The wax has a melting point exceeding 45 ° C., and at least one of behenyl alcohol (mp 65-72 ° C.), stearyl alcohol (mp 54-62 ° C.) and palmityl alcohol (mp 46-55 ° C.), which are higher alcohols. It is more preferable to use a composition mainly composed of seeds or a mixture of two or more kinds.

  The composition ratio of the higher alcohols behenyl alcohol, stearyl alcohol, and palmityl alcohol used as the main component of the wax in the wax may be in the range of 85 to 99% by mass, alone or in a mixture of two or more. preferable. Moreover, solid paraffin (50 mass% or less), stearic acid (10 mass% or less), etc. may be used as a subcomponent having wax properties in the form of replacing the higher alcohols which are the main components.

  In addition, as the wax used for the wax particles according to the present invention, it is possible to use an olefin wax that melts at a temperature of 50 ° C. or higher in addition to the above higher alcohol.

In addition, the wax particles according to the present invention may have a configuration in which a binder is further added when the higher alcohol is used as the main component of the wax.
By adding a binder to the wax, it is possible to fix many phosphors on the wall surface of the discharge cell 4, that is, the partition wall 3 after evaporating the wax component in the step (4) described in detail later. The phosphor layer on 2 is formed thin.
Thereby, it is possible to obtain a plasma display panel having more excellent light emission display characteristics.

As a material of the binder, a resin such as polyisobutyl methacrylate can be used by heating and melting at an addition amount of about 1 to 15% by mass with respect to the wax. Moreover, as a secondary additive component of the binder, ethyl cellulose can be added in an amount of 1 to 10% by mass in the form of substituting polyisobutyl methacrylate, and other resins are compatible with the wax. As long as it can be used in small amounts.
In addition, when the said olefin type wax is used as a main component of a wax, since it is not the wax used as a solvent, it is difficult to add a binder. For this reason, it is preferable to use the higher alcohol as the main component of the wax.

In the wax particles according to the present invention, it is preferable that the composition ratio of the wax and the phosphor is in a range of mass%, and the range of wax: phosphor = 50%: 50% to 70%: 30%. Further, within this range, it is more preferable that wax: phosphor = 60%: 40% so that the composition ratio of wax is larger than that of the phosphor.
The composition ratio between the wax and the phosphor is determined by the target coating thickness of the phosphor layer, but varies depending on the material and the particle size of the phosphor to be used, and must be determined each time.
If the composition ratio of the wax is more than 70% by mass and the phosphor is less than 30% by mass, the amount of the phosphor becomes too small, and it becomes difficult to form a phosphor layer in the discharge cell that provides sufficient light emission characteristics. Become.
If the composition ratio of the wax is less than 50% by mass and the phosphor is more than 50% by mass, the properties of the wax particles as a liquid deteriorate, and the phosphor layer is formed by filling the fine discharge cells with the wax particles. May become difficult.

"Method for producing wax particles"
Although it does not specifically limit as a method to manufacture the wax particle used by this invention, For example, a chemical method, a grinding method, etc. are mentioned.

  In the chemical method, the phosphor and wax are dispersed in hot water, and then the hot water is cooled. At this time, phosphor particles are wrapped and hardened by wax in hot water. Thereby, wax particles in which the phosphor is dispersed in the wax can be obtained.

  In the pulverization method, the phosphor is melted, dispersed in wax, and then solidified. By pulverizing this, wax particles in which the phosphor is dispersed in the wax can be obtained.

Examples of other methods for producing wax particles include the following methods.
First, the phosphor is added to the liquid wax. By placing this in, for example, a funnel and cooling and solidifying while dropping, wax particles in which the phosphor is dispersed in the wax can be obtained.
In addition, in the manufacturing method of these wax particle | grains, it is preferable to carry out integrally by mixing a wax and fluorescent substance beforehand. In each of the above processes, when the wax particles and the phosphor are simply mixed and filled, the phosphor is difficult to disperse in the wax, making it difficult to uniformly deposit the phosphor in the discharge cell. Further, the phosphor particles adhere to the partition walls in the discharge cell during filling, and the removal process in the step (3) becomes difficult.

"Phosphor filling method"
As shown in FIG. 1, in this step, first, the wax particles 5R in which the red (R) phosphor is dispersed in the wax are discharged using a short haired blade with a flock or a rubber blade. The cells 4 are uniformly filled. At this time, the wax particles 5R are filled in all of the plurality of discharge cells 4 provided in the plasma display panel 1. However, the present invention is not limited to this, and a method of filling only the predetermined discharge cells 4 is also possible. It is.

  In the step (1), the discharge cells 4 are filled with the wax particles 5R as described above, and after performing the processes in the steps (2) to (3) described in detail below, the step (1) is performed. ), The discharge cell 4 is filled with wax particles 5G in which a green (G) phosphor is dispersed in wax. Further, after the treatment in each of the steps (2) to (3), the third operation in the step (1) is then performed, and the wax particles in which the blue (B) phosphor is dispersed in the wax. 5B is filled in the discharge cell 4, and processing is performed in the following steps (2) to (3).

  Moreover, it is preferable that the discharge cells 4 are filled with wax particles so that the discharge cells 4 are completely filled with wax particles. The amount of phosphor in cell units can be determined by setting the composition ratio of wax and phosphor. For this reason, it is possible to control the thickness of the phosphor layer formed in the discharge cell by adjusting the composition ratio of the wax and the phosphor.

[Step (2)]
In step (2) of the present embodiment, as shown in FIG. 2, a predetermined discharge cell 4 is irradiated with a laser L among a plurality of discharge cells 4 filled with wax particles 5 (5A, 5B, 5C). In this step, the wax particles 5 in the discharge cell 4 are heated and melted and then solidified to fix the phosphor (see the wax particle layer 51 in FIG. 3) in the discharge cell 4.

"laser"
The laser used in this step is not particularly limited, but it is particularly preferable to use an infrared carbon dioxide (CO ₂ ) laser (wavelength 10.6 μm; continuous, pulse).
In heat-melting with light such as laser, efficient heat-melting is possible by making the light wavelength coincide with the light absorption spectrum of wax or a specific light absorption peak. At this time, it is necessary to make the wavelength width of the light sufficiently narrower than the wavelength width of the light absorption peak. However, since the laser beam has a linear spectrum with a very narrow wavelength width, in general, the spectral width of the light absorption. However, when it is used for heating and melting a wide range of substances, it sufficiently satisfies the conditions enabling efficient heating and melting.

Here, based on the infrared absorption spectrum (IR) characteristics of the higher alcohols constituting the wax particles, the infrared absorption of molecular chains related to heating and melting of the wax mainly composed of higher alcohols will be considered.
The higher alcohol has a molecular chain composed of C—C, C—H, and O—H. Infrared absorption of these molecular chains by respective molecular vibrations is as follows.

(A) C—C: molecular stretching vibration; mainly 83-12.5 μm
(B) C—H: molecular deformation vibration; main 6.9-7.6 μm, molecular stretching vibration; main 3.4-3.7 μm, molecular deformation vibration; sub 11.4-16.7 μm
(C) O—H: molecular stretching vibration: main 2.7-2.8 μm, molecular bending vibration: sub 6.9-8.3 μm

  From the characteristics shown in the above (a) to (c), a carbon dioxide laser having an emission wavelength of 10.6 μm is suitable for applying thermal vibration to the bond main chain of the higher alcohol wax and melting it by laser irradiation. It is clear (see also the Examples section).

In addition, as a laser apparatus used for laser irradiation, since the laser has characteristics suitable for generation of the short pulse light as described above, the pulse width is short in order to instantaneously heat and melt the wax particles ( For example, it is preferable to use an apparatus that generates pulsed light having sufficient energy, for example, in units of μs to ns.
Other lasers that can be used to heat and melt the wax particles include infrared carbon dioxide (CO) laser (wavelength 5.3 μm; continuous, pulse), Er: YAG (wavelength 2.94 μm; pulse), Ho: YAG (wavelength 2.1 μm; pulse) and the like. Among these, Er: YAG (wavelength 2.94 μm) has a characteristic that it is easily absorbed by water and OH.

"Laser irradiation method"
As shown in FIG. 2, in this step, first, a carbon dioxide laser L with a beam spot diameter of 100 μm or less is used at the positions of the discharge cells 4a and 4d among the plurality of discharge cells, and the wax particles 5R. Irradiate with laser. As a result, only the wax particles 5R in the discharge cells 4 irradiated with the laser L are melted by thermal energy, and soon, they are cooled and solidified to form a meniscus, and the wax particle layer 51 (51R) in which the phosphor is dispersed inside. Is fixed to the inner wall of the discharge cell 4.

In the production method of the present invention, even when a semiconductor laser (wavelength: 0.78 μm to 0.98 μm) that irradiates near infrared rays is used, a light absorber (pigment) having a matching wavelength is added to the wax. Thus, it is possible to perform heating and melting. Examples of such a light absorber include polymethine compounds (product number IR-820B; maximum absorption wavelength 0.816 μm, effective absorption wavelength 0.77 μm to 0.85 μm) manufactured by Nippon Kayaku Co., Ltd. Although it is unstable, the company's cyanine compound (product number CY-2; absorption 0.782 μm, CY-4; absorption 0.791 μm, CY-9; absorption 0.787 μm)) and the like can be mentioned.
Moreover, it is necessary to use any of the above light absorbers by adding a small amount of 1% by mass or less. If the amount of the light absorber added to the wax is too large, the wax (and binder) is evaporated and baked in the step (4), and the carbon contained in the light absorber is not left in the phosphor layer. It becomes difficult to do. In consideration of such residual impurities in the phosphor layer, it is preferable to use a carbon dioxide gas laser that does not require the addition of a light absorber to the wax.

[Step (3)]
Step (3) of the present embodiment is a step of removing the wax particles 5 filled in the discharge cells 4 other than the predetermined discharge cell 4.

As shown in FIG. 3, in this step, first, the wax particles in which the red phosphor is dispersed are fixed as the wax particle layer 51R in the discharge cells 4a and 4d. By using it, the wax particles 5R filled in the discharge cells 4b and 4c are removed by blowing or sucking.
The wax particles removed as described above can be collected and reused by, for example, a configuration having a collection means, but the type of collection means is particularly limited. Instead, a suction-type collecting device or the like can be appropriately employed.

[Repeat steps (1) to (3)]
In the present embodiment, as described above, the steps (1) to (3) are repeated for each of the three primary color phosphors dispersed in the wax particles 5, thereby providing a plurality of discharge cells. 4 are filled with wax particles 5R, 5G, and 5B in which phosphors of each color are dispersed, and after cooling by heating and solidification, a meniscus shape is formed, and wax particle layers 51R, in which phosphors of each color are dispersed inside Assume that 51G and 51B are fixed.

  In this example, after fixing the wax particle layer 51R in which the red phosphor is dispersed in the predetermined discharge cell 4 (4a, 4d) by the first operation of each of the above steps (1) to (3), Similarly, by the second operation, the wax particle layer 51G in which the green phosphor is dispersed is fixed in a predetermined discharge cell 4 (here, the discharge cell 4b). Similarly, by the third operation, the wax particle layer 51B in which the blue phosphor is dispersed is fixed in a predetermined discharge cell 4 (here, the discharge cell 4c). As a result, as shown in FIG. 4, the wax particle layers 51 </ b> R, 51 </ b> G, 51 </ b> B in which the phosphors of the respective colors are dispersed are fixed in the plurality of discharge cells 4.

  In addition, in this example, about repetition operation of said each process (1)-(3), filling of a wax particle is carried out for each color of wax particle 5R (red)-wax particle 5G (green)-wax particle 5B (blue). Although it performed in order, it is not limited to this order and can be determined suitably.

[Step (4)]
In the step (4) of the present embodiment, as shown in FIG. 4, wax particles 51 (in which phosphors of respective colors fixed in the discharge cells 4 by the above-described steps (1) to (3) are dispersed. 51R, 51G, 51B), for example, by evaporating the wax components from the discharge cell 4 by a method such as reheating, the phosphors of each color were fixed to the inner wall of the discharge cell 4 as shown in FIG. This is a step of forming phosphor layers R1, R2, G1, G2, B1, and B2.

In this step, for example, using a baking furnace, the wax particle layer 51 fixed in the discharge cell 4 as shown in FIG. 4 is passed through the low temperature zone in the baking furnace at 60 to 150 ° C. It melts by heating at ambient temperature. In this step, the wax particle layer 51 is melted and liquefied, and spreads inside the discharge cell 4 due to surface tension.
Then, in a state where the wax particle layer 51 spreads on the inner wall of the discharge cell, by heating at a high temperature of 380 to 420 ° C., the wax, the binder resin component, etc. contained in the wax particle layer evaporate, and the wax particle layer 51 The phosphors of the respective colors dispersed therein are baked, and phosphor layers R1, R2, G1, G2, B1, and B2 as shown in FIG. 5 can be formed.

  In this step, it is preferable to evaporate all extra components other than the phosphor contained in the wax particle layer. By evaporating and removing all impurities, the purity of the phosphor layer is increased, and a plasma display panel having excellent light emitting display characteristics can be manufactured.

  Further, the phosphor layer formed in this step is formed in a state in which the phosphor layer is thinly formed on the substrate 2 and many phosphors are fixed on the partition wall 3 side in the discharge cell 4. It is preferable. Most preferably, all the phosphors in the discharge cell 4 are phosphor layers fixed on the partition wall 3 side. However, the phosphor layer formed on the substrate 2 is thin and the partition wall 3 side. If a phosphor layer with a large number of phosphors fixed thereto is obtained, a plasma display panel having excellent light emitting display characteristics can be obtained.

[Plasma display panel substrate]
In the method for manufacturing a plasma display panel of the present invention, a substrate of a plasma display panel (PDP) as shown in FIG. 5 can be manufactured by the above-described steps. FIG. 5 is a cross-sectional view of the substrate 1 on the discharge cell side in the plasma display panel.
As shown in FIG. 5, the substrate 1 includes a plate-shaped substrate 2, a partition wall 3 formed on the substrate 2, and a discharge cell 4 defined by the partition wall 3. 4 includes phosphor layers R1, R2, G1, G2, B1, and B2 formed in the above steps (1) to (4).

The base 2 is a flat base made of an insulating material.
As an insulating material which comprises the base | substrate 2, a low melting glass coating film etc. are mentioned, for example.

The partition 3 is a rib-like member provided on the base 2 at a predetermined interval, and is formed of an insulating material such as low-melting glass, a filler mixture, or the like.
The partition walls 3 are, for example, 120 to 130 μm in height from the surface of the base 2 and about 50 μm in width, are arranged on the base 2 at intervals of 250 μm, and are formed in a lattice shape.

The discharge cells 4 (4a, 4b, 4c, 4d) are spaces formed by the base 2 and the barrier ribs 3 and partitioned by the barrier ribs 3 on the base 2. In the partial view illustrated in FIG. 5, each of the reference numerals 4 a, 4 b, 4 c, and 4 d is shown as the discharge cell 4, and illustration in plan view is omitted, but the discharge cell 4 is the surface of the substrate 2. A plurality of substantially rectangular spaces are formed on the entire surface.
The discharge cell 4 is a space where the phosphor fixed in the discharge cell 4 is excited by the ultraviolet rays generated by the discharge in the plasma display panel 1 and emits light. By controlling the discharge light emission, the plasma display panel An image is displayed on the surface.

  As shown in FIG. 5, the phosphor layers R1, R2, G1, G2, B1, and B2 have phosphors of three primary colors fixed on the inner wall of the discharge cell 4, that is, the wall surface of the partition wall 3 and the substrate 2. Formed with. In the example shown in FIG. 5, the phosphor layers R1 and R2 are formed from red (Red), the phosphor layers G1 and G2 are formed from green (Green), and the phosphor layers B1 and B2 are formed from blue (Blue) phosphors. The phosphor layers made of phosphors of the three primary colors are arranged and formed in a predetermined phosphor pattern in the discharge cells 4a, 4b, 4c, and 4d, respectively.

  The plasma display panel using the substrate obtained by the production method of the present invention has a phosphor layer of each color uniformly formed in the discharge cell by the above steps (1) to (4), and has excellent light emitting display characteristics. It becomes.

As described above, according to the plasma display panel manufacturing method described above, the alignment accuracy when forming the phosphor layers R1, R2, G1, G2, B1, and B2 in the discharge cells 4 is improved. A uniform phosphor layer R1, R2, G1, G2, B1, B2 can be formed in the entire discharge cell 4 of the plasma display panel. In addition, since components other than the phosphor evaporate by heating, it is possible to prevent impurities from being mixed into the phosphor layer. Thereby, the light emission characteristics of the discharge cell are enhanced.
Moreover, according to said manufacturing method, irradiation heating to the wax particle 5 by a high-speed scan is attained by using a laser. Thereby, the process time can be shortened, and the phosphor pattern formation in the entire discharge cell 4 can be performed while aligning more accurately, so that the phosphor pattern can be formed with higher accuracy.
In addition, according to the manufacturing method described above, by adopting a method incorporating a cycle process in which the phosphor removed from the discharge cell in the manufacturing process is repeatedly used, the material can be used efficiently and the manufacturing cost can be reduced. It becomes possible.
Therefore, a plasma display panel having excellent display characteristics can be manufactured at a low cost.

  In the above plasma display panel manufacturing method, it is necessary to smoothly fill phosphor particles in a fine discharge cell having a height of 100 to 130 μm and a width of 100 μ to 200 μm. The phosphor is dispersed in wax particles of a size, and is squeezed using a dry-type or wet-type method using a blade with a short hair densely-flocked or a rubber blade, or by an electrostatic coating method. It is possible to efficiently fill the wax particles dispersed.

  In addition, the phosphor particles filled in the discharge cell need to have fluidity. However, the phosphor particles are dispersed in a wax-based substance that is solid at the time of filling and changes to a liquid by heating. It is effective to use the wax particles 5 as one kind of composite particles, and even when the wax particles and the phosphor particles are in a mixed state, they should be in a liquid state by heating and melting after filling the discharge cells. Is possible.

  Further, it is necessary to give the phosphor particles a binder effect for fixing in the discharge cell. As a wax component, a higher alcohol having a melting point of 45 ° C. or higher is used, and an acrylic resin or the like is added to the higher alcohol. The binder effect can be obtained by dissolving the binder.

  In addition, it is necessary to melt and fix the phosphor particles filled in the electrostatic cell for each selected discharge cell, and to form red, green, and blue array patterns by high-speed processing. By narrowing the beam diameter to a small diameter using a laser and controlling the irradiation output and irradiation time, it is possible to heat and melt only the wax fine particles in a predetermined discharge cell, and to fix them. It becomes possible.

  Further, when each of the three primary colors of red, green and blue phosphors is filled in a total of three times, the phosphor particles are completely removed from the discharge cells that do not require filling in each step. As a method for removing particles in the discharge cell, it is necessary to completely remove unnecessary particles by adopting a method of removing particles by blowing off with high-pressure air or a wet method of removing with water or the like. It can be removed. Moreover, the cycle utilization becomes possible by providing the means for collecting the removed particles.

  In addition, the phosphor particles fixed in the discharge cell are melted again, and the barrier that forms the discharge cell by using the action of moving to a narrow space and forming a meniscus by the surface tension, which is a property when the liquid boils. Where it is necessary to move the phosphor particles to the surface, as in the conventional screen printing method, in the process of boiling the liquid, by utilizing the characteristic that the liquid easily moves along the wall surface, It becomes possible to move the phosphor particles dispersed in the particles.

  In addition, in the state where the phosphor layer is formed on the partition wall forming the discharge cell, it is necessary to completely remove the binder and other impurities. By using an acrylic binder as a binder, The binder can be completely removed from the discharge cell.

Hereinafter, the method for producing a plasma display panel of the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.
In this example, the following test was conducted in order to confirm the melting mechanism of the wax when the wax particles formed by dispersing the phosphor in the wax were irradiated with laser.

[Production of wax particles]
First, wax particles according to the present invention were prepared using phosphors and waxes having the following composition.
(1) Phosphor components: red = (Y, Gd) BO ₃ : Eu, green = Zn ₂ SiO ₄ : Mn blue = BaMgAl ₁₀ O ₁₇ : Eu
(2) Wax component: 80% behenyl alcohol, 17% stearyl alcohol, 3% polyisobutyl methacrylate
(3) Composition ratio of wax: phosphor; 50%: 50% (mass%)

[Laser irradiation test]
The wax particles of the present example produced with the above composition were spread on a glass plate, and a heating and melting test by laser irradiation was performed using a carbon dioxide laser (CO ₂ laser: output 25 W).
The dispersion thickness of the wax particles on the glass plate at this time was about 0.6 mm.
Further, the carbon dioxide laser has a ratio of the output shown in the following Table 1 as pulse irradiation, the focus is reduced to a spot diameter of 150 μm, and the scanning speed by the laser is set as the speed shown in Table 1 below, and wax spread on the glass plate. The particles were scanned 10 mm. And in the wax particle spread | diffused on the glass plate, the melting width | variety of the wax particle | grains of the location heated and melted linearly was measured, and it showed in following Table 1 as a melting line | wire width.
Table 1 shows a list of test conditions and measurement results.

From the results shown in Table 1, it is clear that when the wax particles are heated and melted using a carbon dioxide laser, the melting width can be controlled by setting values of the scanning speed and the laser irradiation output.
For example, in Test Example 1, when the scanning speed was 250 mm / s and the output was 2%, the melting line width was 0.2 mm (200 μm), whereas the scanning speed was 20 mm / s with the same output. In the delayed Test Example 2, the melting line width was 0.4 mm (400 μm).
In Test Example 4 in which the scanning speed was 5 mm / s and the output was 6%, the melting line width was 1.5 mm (1500 μm), whereas the scanning speed was 2.5 mm / s with the same output. In the delayed test example 5, the melting line width was 3 mm (3000 μm).
In Example 3 where the scanning speed was 10 mm / s and the output was increased to 8%, the melting line width was 1 to 1.5 mm (1000 to 1500 μm), and heat diffusion was present on the melting line. A non-uniform portion was observed.

  In general, in the plasma display panel, the filling thickness of the wax particles in the depth direction of the discharge cell is estimated to be about 100 μm, but the melting width in this case is considered to be controllable to 100 μm or less from the above test results.

  In this example, in addition to the test using the carbon dioxide gas laser, a test using an Nd: YAG (wavelength 1.064 μm; pulse) laser was also performed. The result was that the particles did not melt.

  From the above results, it is clear that the plasma display panel manufacturing method of the present invention is excellent in alignment accuracy when forming the phosphor layer in the discharge cell, and enables highly precise phosphor pattern formation. .

It is sectional drawing explaining typically an example of the manufacturing method of the plasma display panel of this invention, and is the schematic which shows the state which filled the discharge cell with the wax particle in process (1). It is sectional drawing explaining typically an example of the manufacturing method of the plasma display panel of this invention, and in step (2), the wax particle | grains in a predetermined discharge cell are irradiated with a laser, and it heat-melts, and is set as a wax particle layer. It is the schematic which shows the state fixed. It is sectional drawing which illustrates typically an example of the manufacturing method of the plasma display panel of this invention, and is the schematic which shows the state which removed the wax particle in discharge cells other than a predetermined discharge cell in process (3). . It is sectional drawing which illustrates typically an example of the manufacturing method of the plasma display panel of this invention, and repeats each process (1)-(3) shown in FIGS. 1-3, and it is wax particle | grains in each discharge cell. It is the schematic which shows the state which fixed the layer. It is sectional drawing explaining typically an example of the manufacturing method of the plasma display panel of this invention, and shows the state which evaporated the wax in a discharge cell and formed the fluorescent substance layer in the discharge cell in process (4). FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Base | substrate, 3 ... Partition, 4, 4a, 4b, 4c, 4d ... Discharge cell, 5, 5R, 5G, 5B ... Wax particle, 51, 51R, 51G, 51B ... Wax particle layer, R1, R2, G1, G2, B1, B2 ... phosphor layer

Claims (5)

In a method of manufacturing a plasma display panel, a phosphor layer is formed on the inner walls of a plurality of discharge cells partitioned by barrier ribs provided on a substrate.
Filling the plurality of discharge cells with wax particles in which phosphors of any one of the three primary colors of red (R), green (G) and blue (B) are dispersed in wax Step (1) to perform,
Next, among the plurality of discharge cells filled with the wax particles, a predetermined discharge cell is irradiated with a laser to heat and melt the wax particles in the discharge cell, and then solidify the phosphor in the discharge cell. Fixing step (2);
Next, the step (3) of removing wax particles filled in the discharge cells other than the predetermined discharge cells in order,
After repeating the steps (1) to (3) for each of the three primary color phosphors dispersed in the wax particles,
Next, a method of manufacturing a plasma display panel, comprising the step (4) of evaporating wax in the discharge cell and fixing the phosphor to the inner wall of the discharge cell to form a phosphor layer. .   2. The method of manufacturing a plasma display panel according to claim 1, wherein the wax particles removed in the step (3) are reused in the step (1).   The method of manufacturing a plasma display panel according to claim 1, wherein the laser is a carbon dioxide laser.   4. The plasma according to claim 1, wherein the wax is an organic substance having a melting point of 40 to 200 ° C., and is a wax-like substance that is heated and melted by a transmission wavelength of the laser. Display panel manufacturing method. 5. The wax according to claim 4, wherein the wax has a melting point of more than 45 ° C. and is a composition mainly composed of at least one of behenyl alcohol, stearyl alcohol, and palmityl alcohol, or a mixture of two or more thereof. A method for producing a plasma display panel as described in 1.

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