JP3768153B2 - Method for forming bus electrode for plasma display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming an electrode for a plasma display panel (hereinafter referred to as PDP), and more particularly to a method for forming a bus electrode disposed on a front plate of a PDP.
[0002]
[Prior art]
In the PDP, a front plate in which a transparent electrode, a bus electrode, a dielectric layer, a protective layer, and the like are formed on a glass substrate is opposed to a back plate in which an address electrode, a partition, a phosphor, and the like are formed on the glass substrate. It is a device that displays by irradiating phosphors with ultraviolet rays generated from gas by enclosing gas in a space formed between them and causing plasma discharge.
[0003]
The bus electrode formed on the front plate of the PDP is one of the important factors to improve the contrast of the display screen in addition to transmitting the scan / sustain pulse. For this purpose, a bus electrode having a structure in which a black electrode and a conductive electrode are sequentially laminated on a front plate is usually employed. With such a stacked structure, the electrode becomes black when viewed from the display surface, and the contrast of the display screen can be improved by reducing the external light reflectance. The line width of the bus electrode pattern is usually about 50 to 100 μm. This is for the following reason. If the line width is increased, the reflection of external light can be further reduced and the display contrast is further improved. However, since the light emission from the cell is blocked by the electrodes, the luminance is deteriorated. Further, if the thickness is reduced, the resistance value increases, and it becomes difficult to drive the PDP.
[0004]
[Problems to be solved by the invention]
A bus electrode having such a laminated structure can be formed by printing and drying a photosensitive black electrode paste, further printing and drying a photosensitive conductive electrode paste, and performing exposure, development, and baking.
[0005]
However, in this firing process, gas is generated due to thermal decomposition of the resin component in the electrode layer or reduction of the glass frit. When the following phenomenon occurs, this cracked gas is not discharged into the atmosphere but is confined in the electrode layer, causing the electrode to swell, and the swell to rupture, thereby causing disconnection.
(1) If the resin contained in the black electrode layer or the decomposition gas of the glass frit is generated before the resin contained in the conductive electrode layer is sufficiently burned out, the resin in the conductive electrode layer prevents the gas from permeating. End up.
(2) When the metal particles and glass frit of the conductive electrode layer become fine, the space between the particles becomes narrow, and thus gas permeation is hindered.
(3) When the conductive electrode layer is sintered, there is no gas escape route, which hinders gas permeation.
(4) When the above phenomena (1), (2), and (3) overlap.
[0006]
Due to the pressure of the decomposition gas accumulated in this way, the electrode expands, leading to chipping or disconnection of the electrode. The size of the electrode bulge and the rupture conditions vary depending on the type of electrode material, the type of glass frit, the type of resin, the firing temperature, the state after firing, and the like.
[0007]
If there is a firing step in the subsequent step of the electrode firing step (for example, firing of a dielectric), the gas confined in the electrode layer in the previous firing step due to firing further expands, or the glass frit or decomposition can be completed. Further gas is generated from the unresined resin, resulting in new electrode swelling, increasing the occurrence of electrode chipping and disconnection. For this reason, it is necessary to take measures to release the gas into the atmosphere.
[0008]
Thus, for example, Japanese Patent Application Laid-Open No. 2001-084912 discloses a method in which a black electrode paste contains a resin having a higher thermal decomposition temperature than the resin contained in the conductive electrode paste. This technique is a measure against the above (1), the resin in the conductive electrode layer is burned out first, and the resin decomposition gas in the black electrode layer permeates through the space blocked by the resin, This is a method of suppressing the occurrence of electrode swelling and distortion. However, this method is not sufficient as it is not a solution for the cases (2) and (3) described above.
[0009]
Therefore, the main object of the present invention is for a PDP that can be efficiently released into the atmosphere without the resin decomposition gas of the black electrode layer accumulating in the electrode layer when the PDP electrode (bus electrode) is formed by firing . The object is to provide a method of forming an electrode (bus electrode) .
[0011]
[ Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 relates to a method of forming a bus electrode for a plasma display panel, in a mode of covering a transparent electrode provided on the main surface on one main surface of a transparent substrate. A step of sequentially forming a photosensitive first resin layer containing a metal oxide and a photosensitive second resin layer containing metal particles, the first resin layer and the second resin layer Is a multilayer film pattern composed of the first resin layer and the second resin layer, and penetrates the second resin layer and is uniform in the length direction. Forming a bus electrode pattern having a plurality of gas discharge holes distributed in a shape, uniform size, and uniform spacing on the transparent electrode; firing the multilayer film pattern; A first electrode layer containing an oxide and a first electrode layer containing the metal particles; Forming a linear bus electrode composed of a multi-layer electrode layer and a multi-layer electrode layer, and when firing the multi-layer film pattern, the gas generated in the first resin layer is allowed to flow through the second resin layer. It escapes from the gas discharge hole which penetrates.
[0012]
[Means for Solving the Problems]
The invention according to claim 2 relates to a method of forming a bus electrode for a plasma display panel. The ultraviolet curable type containing a metal oxide by screen printing on a transparent electrode provided on one main surface of a transparent substrate. Alternatively, a step of forming a multilayer film pattern by sequentially stacking a thermosetting first resin layer pattern and an ultraviolet curable or thermosetting second resin layer pattern containing metal particles, Calcining to form a linear bus electrode comprising a multilayer electrode layer of a first electrode layer containing the metal oxide and a second electrode layer containing the metal particles, In the step of forming the multilayer film pattern, a plurality of gases that penetrate the second resin layer pattern and are distributed so as to have a uniform shape, a uniform size, and a uniform interval in the length direction Form discharge holes at the same time Both the time of firing the multilayer film pattern, characterized in that escape the first resin layer pattern generated gas from the gas discharge hole through the second resin layer.
[0013]
The invention described in claim 3 relates to a method of forming a bus electrode for a plasma display panel, and contains a metal oxide so as to cover the transparent electrode on a transparent substrate provided with a transparent electrode on one main surface. A step of coating a photosensitive film comprising a multilayer film of a photosensitive first resin layer and a photosensitive second resin layer containing metal particles; and exposing and developing the photosensitive film, A multilayer film pattern consisting of the second resin layer and the second resin layer, which penetrates the second resin layer and has a uniform shape, a uniform size and a uniform spacing in the length direction. Forming a bus electrode pattern having a plurality of gas discharge holes distributed so as to be on the transparent electrode, firing the multilayer film pattern, and forming the first electrode layer containing the metal oxide, Multilayer of second electrode layer containing metal particles Forming a polar layer, and when firing the multilayer film pattern, the gas generated in the first resin layer is released from the gas discharge hole penetrating the second resin layer. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an electrode structure for a PDP according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1 and 2, the electrode for PDP (bus electrode 10) of the present embodiment is formed on the transparent electrode 2 on the surface of the transparent substrate 1 such as glass, and the black electrode layer 3 and the conductive electrode layer 4 are formed. It is comprised from the two-layer laminated film. A rectangular hole 5 reaching the surface of the transparent electrode 2 is formed in the bus electrode 10. This hole 5 functions as a discharge path for gas generated from the electrode material in the baking process for forming the bus electrode, and can prevent defects such as swelling and chipping of the bus electrode. The conductive electrode layer 4 may be composed of a multilayer film.
[0015]
Next, a first method for forming a bus electrode according to the present invention will be described. In this method, a bus electrode is formed using a photosensitive paste, and is composed of two steps: (1) an electrode paste application step and (2) an electrode pattern firing step. Each process will be described below with reference to FIG.
(1) Electrode paste application process First, as shown in FIG. 3A, the transparent electrode 2 is formed on a transparent substrate 1 such as glass using a material such as indium tin oxide (ITO) or tin oxide (SnO2). Pattern. A photosensitive resin (photosensitive black electrode paste) to which at least one kind of metal oxide such as Ru, Co, Cu, Mn, and Cr is added is coated with a 200-400 mesh screen so as to have a desired thickness. The black electrode layer 3 is formed by coating with a screen printing machine (FIG. 3B). Thereafter, the paste is dried at a temperature of 100 ° C. or lower using an IR (infrared) drying oven or a hot air drying oven.
[0016]
Next, a 200 to 400 mesh screen of photosensitive resin (photosensitive metal electrode paste) to which at least one kind of conductive particles such as Ag, Au, Pd, Pt, Cu, and Al is added so as to have a desired thickness. Is applied onto the black electrode layer 3 by a screen printer to form the conductive metal layer 4. Thereafter, drying is performed again at a temperature of 100 ° C. or less using an IR drying furnace or a hot air drying furnace (FIG. 3C). Thus, the thickness of the laminated electrode structure became 10-20 micrometers.
(2) Electrode pattern exposure process The stacked electrodes are irradiated with ultraviolet rays from an ultrahigh pressure mercury lamp through a ladder-shaped exposure mask 6 in which a rectangular shape is drawn in a stripe pattern having a line width of 100 μm (FIG. 3D). ). As a result, an unexposed area 7 corresponding to the rectangular shape drawn on the exposure mask exists in the exposed electrode pattern area (FIG. 3E). The length of the rectangular hole 5 serving as a gas discharge path in the direction perpendicular to the electrode direction (hereinafter referred to as the horizontal width) and the distance in the electrode direction can be freely determined, but the preferred value of the horizontal width when the electrode pattern width is 100 μm. Is 40 to 60 μm, and a preferable value of the interval is 20 to 40 μm. Such a shape and arrangement of the holes 5 can maintain the electric resistance of the electrode layer at a predetermined value, and can prevent occurrence of disconnection due to electrode swelling or rupture. Here, the rectangular shape of the exposure mask is designed in consideration of the amount of shrinkage of the electrodes.
(3) Electrode pattern development process Since an alkali-soluble organic resin is used for the resin of the photosensitive electrode paste, development can be performed with an alkaline aqueous solution. Any alkaline aqueous solution may be used, but in general, development using a sodium carbonate aqueous solution can form the bus electrode 10 pattern and the gas discharge path hole 5 (FIG. 3F). )). The concentration of the aqueous sodium carbonate solution is preferably about 0.1 to 1.0% by weight. If the concentration is 0.1% by weight or less, the concentration is too thin, so that it is difficult to form a pattern, and a residue tends to remain. If the concentration is 1.0% by weight or more, the density is too high, so that over-development occurs and the exposed area is easily peeled off.
(4) Electrode pattern firing step After development, firing is performed at a peak temperature of 500 to 600 ° C in an air atmosphere. When the temperature is 500 ° C. or lower, the resin (binder) in the paste is not sufficiently volatilized, so that the conductivity of the electrode is lowered. Since the gas discharge path 5 is formed in the bus electrode, the resin decomposition gas in the black electrode layer 3 passes through the side surface of the gas discharge path (hole 5) and is released into the atmosphere. Therefore, the decomposition gas does not accumulate in the electrode layer, and a problem from electrode swelling to disconnection is suppressed.
[0017]
In the above bus electrode forming method of the present invention, the gas discharge path is formed simultaneously with the electrode pattern formation. Therefore, the gas discharge path can be easily formed with the same number of steps as in the prior art.
[0018]
Next, a second method for forming a bus electrode according to the present invention will be described.
[0019]
In the first method for forming a bus electrode according to the present invention, an electrode is formed using a photosensitive paste, but an ultraviolet curable or thermosetting electrode paste is printed using a screen plate on which a pattern is drawn. It can also be formed by a method (pattern printing). The bus electrode forming step using the method of printing the electrode paste is composed of two steps: (1) an electrode paste applying step and (2) an electrode pattern firing step. Each process will be described below with reference to FIG.
(1) Electrode paste coating process Examples of screen plates used in printing include a pattern in which a rectangular closed portion is provided in an opening pattern (in an electrode pattern) discharged from a paste. The size of the rectangular shape and the like are determined in the same manner as in the first bus electrode forming method of the present invention.
[0020]
Metal oxide such as Ru, Co, Cu, Mn, and Cr on a transparent substrate 1 such as glass on which a transparent electrode 2 such as indium tin oxide (ITO) and tin oxide (SnO2) is formed (FIG. 4A). The black electrode paste to which is added is applied with a screen printer using a 200-400 mesh screen so as to have a desired thickness. Thereafter, the paste is dried at a temperature of 100 ° C. or lower using an IR drying furnace or a hot air drying furnace to form a pattern of the black electrode layer 3 (FIG. 4B).
[0021]
Next, a metal electrode paste to which conductive particles such as Ag, Au, Pd, Pt, Cu, and Al are added is applied with a screen printer using a 200-400 mesh screen so as to have a desired thickness. .
[0022]
Thereafter, drying is performed again at a temperature of 100 ° C. or lower using an IR drying furnace or a hot air drying furnace to form the conductive electrode layer 4 (FIG. 4C). Thus, the thickness of the bus electrode 10 laminated | stacked became 10-20 micrometers. In addition, when a black electrode paste or a metal electrode paste is an ultraviolet curing type, an ultraviolet curing furnace is used for drying.
(2) Electrode pattern firing step After printing, firing is performed at a peak temperature of 500 to 600 ° C. in an air atmosphere. When the temperature is 500 ° C. or lower, the resin (binder) in the paste is not sufficiently volatilized, so that the conductivity of the electrode is lowered. Since the gas discharge path hole 5 is formed in the bus electrode 10, the resin decomposition gas in the black electrode layer passes through the side surface of the hole 5 and is released into the atmosphere. Therefore, although the first method for forming the bus electrode of the present invention is different from the process described above, the decomposition gas does not accumulate in the electrode layer, and the problem from the electrode swelling to the disconnection is suppressed.
[0023]
Next, a third method for forming a bus electrode according to the present invention will be described.
[0024]
In the first and second methods for forming a bus electrode according to the present invention, the electrodes are formed using a photosensitive paste or a pattern printing method. However, the electrodes can be formed using a photosensitive sheet film. The bus electrode forming process using the photosensitive film is composed of four processes: (1) an electrode sheet film coating process, (2) an electrode pattern exposure process, (3) an electrode pattern developing process, and (4) an electrode pattern firing process. Yes. Each process will be described below with reference to FIG.
(1) Electrode sheet film coating step On a transparent substrate 1 such as glass on which the transparent electrode 2 is formed (FIG. 5 (a)), a metal oxide such as Ru, Co, Cu, Mn, or Cr is used using a laminator device. The photosensitive black electrode layer 3 to which an object is added and the photosensitive metal electrode layer 4 to which conductive particles such as Ag, Au, Pd, Pt, Cu, and Al are added are coated (see FIG. FIG. 5B).
(2) Electrode pattern exposure step The laminated electrodes are irradiated with ultraviolet rays from an ultrahigh pressure mercury lamp through the same exposure mask 6 as in the first method of forming a bus electrode of the present invention (FIG. 5C). . Thereby, an unexposed area 7 corresponding to the rectangular shape drawn on the exposure mask exists in the exposed electrode pattern area (FIG. 5D).
(3) Electrode pattern development process Also in the photosensitive film 20, the alkali-soluble organic resin is used like the photosensitive paste, and it can develop by using aqueous alkali solution. The photosensitive film 20 is developed using, for example, a 0.5 wt% sodium carbonate aqueous solution to form the bus electrode 10 pattern and the gas discharge path hole 5. (FIG. 5 (e)).
(4) Electrode pattern firing step After development, firing is performed at a peak temperature of 500 to 600 ° C in an air atmosphere. Since the gas discharge path hole 5 is formed in the bus electrode, the resin decomposition gas in the black electrode layer passes through the side surface of the hole 5 and is released into the atmosphere. Therefore, the decomposition gas does not accumulate in the electrode layer, and problems from electrode swelling to disconnection are suppressed.
[0025]
In the above description of the bus electrode of the present invention, the shape of the hole 5 is a rectangular shape in horizontal cross section, but the shape of the hole 5 may be a circle, an ellipse, or other square shapes. FIG. 6 is a perspective view of the main part of the bus electrode when the hole has a circular cross-sectional shape. 7 and 8 are perspective views showing examples in which circular holes are provided in a plurality of rows or staggered shapes. It is preferable to set the interval between the circular or elliptical holes to 40 μm or less.
[0026]
【The invention's effect】
As described above, in the present invention, by providing the gas discharge path hole in the bus electrode of the PDP, the gas generated from the electrode layer in the firing process of forming the bus electrode can be efficiently released to the outside. Further, the occurrence of swelling or chipping of the bus electrode can be prevented, and the effects of improving the quality of the PDP and reducing the manufacturing cost can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an electrode structure for a PDP according to an embodiment of the present invention.
2 is a cross-sectional view taken along line AA ′ of FIG.
FIG. 3 is a cross-sectional view for explaining a first formation step of a bus electrode according to the present invention.
FIG. 4 is a cross-sectional view for explaining a second step of forming a bus electrode according to the present invention.
FIG. 5 is a cross-sectional view for explaining a third step of forming a bus electrode according to the present invention.
FIG. 6 is a perspective view showing another example of the shape of a hole for a gas discharge path provided in the bus electrode of the present invention.
FIG. 7 is a perspective view showing another example of the shape of a hole for a gas discharge path provided in the bus electrode of the present invention.
FIG. 8 is a perspective view showing another example of the shape of a hole for a gas discharge path provided in the bus electrode of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Transparent electrode 3 Black electrode layer 4 Conductive electrode layer 5 Hole 6 Exposure mask 7 Unexposed area 10 Bus electrode 20 Photosensitive film

Claims (3)

A photosensitive first resin layer containing a metal oxide and a photosensitive second resin containing metal particles on a main surface of the transparent substrate so as to cover the transparent electrode provided on the main surface. Forming a resin layer in sequence, and exposing and developing the first resin layer and the second resin layer to form a multilayer film pattern including the first resin layer and the second resin layer. And a bus electrode having a plurality of gas discharge holes that are distributed so as to penetrate the second resin layer and have a uniform shape, a uniform size, and a uniform interval with respect to the length direction. A step of forming a pattern on the transparent electrode, and a multilayer electrode layer comprising a first electrode layer containing the metal oxide and a second electrode layer containing the metal particles by firing the multilayer film pattern Forming a linear bus electrode comprising:
A method of forming a bus electrode for a plasma display panel, wherein when the multilayer film pattern is baked, a gas generated in the first resin layer is released from the gas discharge hole penetrating the second resin layer. An ultraviolet curable or heat-containing first resin layer pattern containing a metal oxide and a heat-curable first resin layer pattern and metal particles by screen printing on a transparent electrode provided on one main surface of the transparent substrate. A step of sequentially stacking a curable second resin layer pattern to form a multilayer film pattern;
A step of firing the multilayer film pattern to form a linear bus electrode comprising a multilayer electrode layer of a first electrode layer containing the metal oxide and a second electrode layer containing the metal particles. Including
In the step of forming the multilayer film pattern, a plurality of distributions are made so as to penetrate the second resin layer pattern and have a uniform shape, a uniform size, and a uniform interval with respect to the length direction. While simultaneously forming the gas discharge hole,
A method of forming a bus electrode for a plasma display panel, wherein the gas generated in the first resin layer pattern is released from the gas discharge hole penetrating the second resin layer when firing the multilayer film pattern . A photosensitive first resin layer containing a metal oxide and a photosensitive second resin layer containing metal particles so as to cover the transparent electrode on a transparent substrate provided with a transparent electrode on one main surface; A step of coating a photosensitive film comprising a multilayer film of
Said photosensitive film is exposed and developed, a multi-layered film pattern composed of the first resin layer and the second resin layer, passes through the second resin layer, one with respect to the longitudinal Forming a bus electrode pattern having a plurality of gas discharge holes distributed on the transparent electrode so as to have a uniform shape, a uniform size, and a uniform interval ;
Firing the multilayer film pattern to form a multilayer electrode layer of the first electrode layer containing the metal oxide and the second electrode layer containing the metal particles,
A method of forming a bus electrode for a plasma display panel, wherein when the multilayer film pattern is baked, a gas generated in the first resin layer is released from the gas discharge hole penetrating the second resin layer.

Images